The oral second-generation antipsychotic drug iloperidone (Fanapt – Vanda) has been approved by the FDA for acute treatment of manic or mixed episodes associated with bipolar I disorder in adults. First approved in 2009 for treatment of schizophrenia, iloperidone is the eighth second-generation antipsychotic to be approved for acute treatment of manic or mixed episodes of bipolar I disorder (see Table 1).

Bipolar disorder is characterized by episodes of mania, hypomania, and depression. Recurrences of manic or (more frequently) depressive symptoms are common. About 15-20% of patients with bipolar disorder die by suicide.

A selective serotonin reuptake inhibitor (SSRI) is generally used for initial treatment of major depressive disorder (MDD). A serotonin-norepinephrine reuptake inhibitor (SNRI), bupropion (Wellbutrin SR, and others), and mirtazapine (Remeron, and others) are reasonable alternatives. Improvement in symptoms can occur within the first two weeks of treatment with these drugs, but a substantial benefit may not be achieved for 4-8 weeks.

Anxiety disorders (generalized anxiety disorder, panic disorder, social anxiety disorder, and various phobias) are the most common form of psychiatric illness. They can be treated effectively with cognitive behavioral therapy (CBT) and/or pharmacotherapy.

The FDA has approved the second-generation antipsychotic drug cariprazine (Vraylar — Abbvie) for adjunctive treatment of major depressive disorder (MDD) in adults. Cariprazine was previously approved for treatment of schizophrenia and bipolar depression, and for acute treatment of manic or mixed episodes associated with bipolar I disorder.

The oral second-generation antipsychotic drug lumateperone (Caplyta – Intra-Cellular Therapies), which was approved by the FDA in 2020 for treatment of schizophrenia, is now approved for use as monotherapy or as an adjunct to lithium or valproate for treatment of depressive episodes associated with bipolar I or II disorder in adults.

The FDA has approved pitolisant (Wakix – Harmony), a histamine-3 (H₃)-receptor antagonist/inverse agonist, for treatment of excessive daytime sleepiness (EDS) or cataplexy in adults with narcolepsy. It is the first H₃-receptor antagonist/inverse agonist to become available in the US and the first non-controlled substance to receive FDA approval for these indications. Pitolisant has been available in Europe since 2016.

Irritable bowel syndrome (IBS) is a common disorder characterized by recurrent abdominal pain and altered bowel habits, often accompanied by bloating.IBS is classified according to the predominant bowel symptom as IBS with constipation (IBS-C), IBS with diarrhea (IBS-D), mixed type (IBS-M), or unclassified (IBS-U). Alterations in the microbiome, stress responses, sensory and motor function of the gut, and host genetic factors may be contributing factors. Since the exact cause of IBS is unknown, the goal of treatment is symptom control.

View the Table: Safety of Drugs for IBS in Pregnancy and Lactation

Complete remission of symptoms is the goal of treatment for major depressive disorder; a partial response is associated with an increased risk of relapse. Improvement in symptoms can occur within the first two weeks of treatment with an antidepressant, but it may take 4-8 weeks to achieve a substantial benefit. Following successful treatment of a first major depressive episode, antidepressant treatment should be continued at the same dose for at least 4-9 months to consolidate recovery. In patients with recurrent depressive episodes, long-term maintenance treatment can reduce the risk of relapse.

Anxiety disorders (generalized anxiety disorder, panic disorder, social anxiety disorder, and various phobias) are the most common form of psychiatric illness. They can be treated effectively with cognitive behavioral therapy (CBT) and/or pharmacotherapy. Obsessive-compulsive disorder and posttraumatic stress disorder are now considered separate entities in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5); they can also be treated with CBT and many of the same drugs.

Irritable bowel syndrome (IBS) is a common disorder characterized by chronic, intermittent abdominal pain or discomfort and altered bowel habits. It is subtyped according to the predominant bowel symptom as IBS with constipation (IBS-C), IBS with diarrhea (IBS-D), mixed type (IBS-M), or unclassified (IBS-U). Since the exact cause of IBS is unknown, the goal of treatment is symptom control.

Complete remission of symptoms is the goal of antidepressant therapy; partial response is associated with an increased risk of relapse. Improvement can occur within the first two weeks of drug therapy, but it may take 4-8 weeks to achieve a substantial benefit. Fewer than 50% of patients with depression respond to first-line pharmacotherapy, and the rate of response decreases with each subsequent drug trial. Following remission after a first episode of depression, many experts recommend continuing antidepressant treatment at the same dose for at least 6-12 months to consolidate recovery. For patients with recurrent depressive episodes, long-term maintenance therapy can reduce the risk of recurrence.

The FDA has approved the oral, once-daily, second-generation antipsychotic brexpiprazole (Rexulti – Otsuka/Lundbeck) for treatment of schizophrenia and as an adjunct to antidepressants for treatment of major depressive disorder (MDD). Aripiprazole (Abilify), a structurally similar second-generation antipsychotic also comarketed by Otsuka (with BMS), recently became available generically.

The treatment of atrial fibrillation includes anticoagulation, rate control, and rhythm control. New US guidelines for the management of atrial fibrillation have recently been published.

The FDA has approved levomilnacipran (lee" voe mil na' si pran; Fetzima – Forest), a serotonin and norepinephrine reuptake inhibitor (SNRI), for treatment of major depressive disorder. Levomilnacipran is the more active enantiomer of milnacipran (Savella), which was approved in 2009 for management of fibromyalgia. Fetzima has not been studied in fibromyalgia.

The primary symptoms of menopause are vasomotor and genitourinary. Vasomotor symptoms ("hot flashes") cause daytime discomfort and chronic insomnia. A thin, dry vaginal lining and thin urethral mucosa can cause vaginal and vulvar irritation, pain during intercourse, and an increased risk for urinary tract infection.

Vilazodone (Viibryd – Forest), a selective serotonin reuptake inhibitor (SSRI) and partial 5-HT_1A receptor agonist, has been approved by the FDA for treatment of depression. It has been claimed to have no sexual side effects and not to cause weight gain.

Attention-deficit/hyperactivity disorder (ADHD) is a disruptive behavior disorder that occurs in about 5% of school-age children, most often in boys, and frequently persists into young adulthood.

Adults with a body mass index (BMI=kg/m²) of 25-<30 are considered overweight; those with a BMI of ≥30 are considered obese.

Drugs are not the only treatment for mood disorders. Psychotherapy remains an important component in the management of these disorders, and electroconvulsive therapy (ECT) has a long history of efficacy and safety when drugs are ineffective, poorly tolerated or cannot be used. Some drugs are recommended here for indications that have not been approved by the FDA.

Use of a selective serotonin reuptake inhibitor (SSRI) is common in women taking tamoxifen (Nolvadex, and others) for breast cancer, both to treat depression and to decrease hot flashes. However, tamoxifen must be metabolized by CYP2D6 to become pharmacologically fully active (MJ Higgins et al. J Natl Compr Canc Netw 2009; 7:203), and the SSRIs fluoxetine (Prozac, and others) and paroxetine (Paxil, and others) are strong inhibitors of CYP2D6. Sertraline (Zoloft, and others) inhibits CYP2D6 to a lesser extent. Citalopram (Celexa, and others) and escitalopram (Lexapro), the 2 other SSRIs approved for treatment of depression, are only weak inhibitors of CYP2D6.

Two observational studies presented at a recent meeting of the American Society of Clinical Oncology (45th annual meeting, May 29-June 2, 2009, Orlando, FL abstracts CRA508, CRA509) examined the effect of strong inhibitors of CYP2D6 on the success rate of tamoxifen in preventing recurrence of breast cancer. One found that women who took fluoxetine, paroxetine or sertraline (or bupropion, duloxetine, terbinafine, quinidine or long-term diphenhydramine) with tamoxifen had a higher 2-year recurrence rate (13.9% vs. 7.5%). The other study found no association between cancer recurrence and use of a CYP2D6 inhibitor.

There is no good evidence that any one SSRI is more effective than any other for treatment of depression. For women who are taking tamoxifen and need to begin treatment with an SSRI to treat depression, citalopram or escitalopram might be the safest choice (Treat Guidel Med Lett 2006; 4:35). Use of an SSRI to treat hot flashes in women taking tamoxifen should probably be reconsidered.

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Tetrabenazine (Xenazine - Ovation Pharmaceuticals), an old drug first synthesized 50 years ago for treatment of schizophrenia, was recently approved by the FDA for the treatment of chorea associated with Huntington's disease. It has been available in other countries for decades.

Depression occurs in up to 20% of pregnant women, and the use of selective serotonin reuptake inhibitors (SSRIs) in these women has been increasing. Maternal depression has itself been associated with intrauterine growth problems and low birth weight, so the risks of exposure to antidepressants during pregnancy must be weighed against the risks of untreated depression, which also include self-harm, poor bonding and poor parenting. SSRIs available in the US for treatment of depression include citalopram (Celexa, and others), escitalopram (Lexapro), fluoxetine (Prozac, and others), paroxetine (Paxil, and others) and sertraline (Zoloft).

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Fluvoxamine maleate, a selective serotonin reuptake inhibitor (SSRI) that has been available for many years in an immediate-release formulation (Luvox, and others) for treatment of obsessive-compulsive disorder (OCD) in children and adults, has now been approved by the FDA in an extended-release formulation (Luvox CR - Jazz Pharmaceuticals) for treatment of OCD and social anxiety disorder (SAD) in adults.

A reader expressed disappointment that our recent listing of “Some Warfarin Drug Interactions”1 did not include acetaminophen. Perhaps it should have. Acetaminophen can increase the anticoagulant effect of warfarin, particularly with continued use, but it does so inconsistently. The mechanism of this interaction has not been established, but may be related to an acetaminophen metabolite inhibiting vitamin K-epoxide reductase, the target for warfarin’s anticoagulant effect.2

Patient susceptibility varies, possibly on a genetic basis; occasional use of acetaminophen generally has little or no effect on the international normalized ratio (INR) in patients on chronic warfarin therapy, but in some, even a few grams of the drug may cause a dramatic increase in INR. One study in healthy subjects found no effect of acetaminophen 4 g per day for 2 weeks, while another study in patients with the same acetaminophen dose for the same period of time found a moderate increase in INR.3,4 It might be prudent to monitor INR in patients on chronic warfarin therapy more closely than usual when they take more than 2 g per day of acetaminophen for more than a few days.

1. Pharmacogenetic-based dosing of warfarin. Med Lett Drugs Ther 2008; 50:39.
2. HH Thijssen et al. Paracetamol (acetaminophen) warfarin interaction: NAPQI, the toxic metabolite of paracetamol, is an inhibitor of enzymes in the vitamin K cycle. Thromb Haemost 2004; 92:797.
3. D Kwan et al. The effects of acetaminophen on pharmacokinetics and pharmacodynamics of warfarin. J Clin Pharmacol 1999; 39:68.
4. I Mahe et al. Paracetamol: A haemorrhagic risk factor in patients on warfarin. Br J Clin Pharmacol 2005; 59:371.

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The FDA has approved the marketing of desvenlafaxine (Pristiq - Wyeth), the main active metabolite of venlafaxine (Effexor, and others - Wyeth), for treatment of major depressive disorder. Venlafaxine, a norepinephrine and serotonin reuptake inhibitor (SNRI), is available generically as an immediate-release tablet. Venlafaxine extended-release capsules (Effexor XR) are scheduled to go off-patent in 2010.

Warfarin sodium (Coumadin, and others) and other coumarin anticoagulants prevent thrombosis, but patient response is highly variable and overanticoagulation can lead to hemorrhage. Genotyping patients for single nucleotide polymorphisms (SNPs) that affect coumarin metabolism and sensitivity may help clinicians estimate the therapeutic warfarin dose. The FDA has added a note to warfarin labeling recommending lowrange doses for patients with such genetic variations. Commercial tests for these variants are now available and cost about $500 per test.

Losing even a small amount of weight and increasing physical activity can prevent some of the complications of obesity, particularly type 2 diabetes. Diet and exercise are the preferred methods for losing weight but are associated with high long-term failure rates. Drugs may help some patients, but all currently available drugs for weight reduction have drawbacks. Gastric surgery can produce marked weight loss in the severely obese, but long-term data on safety are limited.

Nebivolol (Bystolic - Forest) is a new beta-blocker that has been approved by the FDA for treatment of hypertension. It has been marketed in Europe since 1999 for treatment of hypertension and heart failure.

Drugs are not the only treatment for psychiatric illness. Psychotherapy remains an important component in the management of these disorders, and cognitive behavioral therapy (CBT) is used for many of them as well. Electroconvulsive therapy (ECT) has a long history of efficacy and safety when drugs are ineffective or cannot be used.

Duloxetine hydrochloride (Cymbalta - Lilly), a selective serotonin and norepinephrine reuptake inhibitor (SNRI) available for treatment of depression, has also been approved by the FDA for treatment of neuropathic pain associated with diabetic peripheral neuropathy (DPN). Duloxetine is one of two drugs approved specifically for management of neuropathic pain due to diabetes; the other, pregabalin (Lyrica - Pfizer), will be marketed soon and will be reviewed in the next issue of The Medical Letter.

The FDA has reported that 5106 elderly patients with dementia treated with atypical (second generation) antipsychotics in 17 randomized controlled trials had a higher mortality rate (4.5% vs. 2.6%) than those receiving placebo. Most of the deaths were due to cardiovascular and infectious causes (such as pneumonia). The drugs used in the trials were aripiprazole (Abilify), olanzapine (Zyprexa), quetiapine (Seroquel), and risperidone (Risperdal). As the increase in mortality was considered a class effect, the FDA advisory also included ziprasidone (Geodon), clozapine (Clozaril) and the olanzapine/fluoxetine combination (Symbyax). The manufacturers of all of these drugs will be required to add a "black box" warning to their labeling.

An extended-release formulation of carbamazepine, available since 1997 for treatment of epilepsy, has now been approved under a new name, Equetro, for acute mania and mixed episodes of bipolar disorder. Although the drug was effective in some patients for up to 6 months, it has not been approved for maintenance treatment. Carbamazepine has not been shown to be more effective than lithium or valproate, and it can cause serious adverse effects.

Alprazolam, a short-acting benzodiazepine, is one of the most widely prescribed drugs in the US. It is approved by the FDA for treatment of anxiety and panic disorder. An extended-release formulation, Xanax XR, which can be taken once a day, recently became available for panic disorder.

Estrogen is the most effective treatment for menopausal vasomotor symptoms (hot flashes), but the Women's Health Initiative study found that women who took estrogen plus a progestin for more than 5 years were at increased risk for myocardial infarction, stroke, pulmonary emboli, deep vein thrombosis, breast cancer, and possibly dementia. Are there effective alternatives?

Duloxetine hydrochloride (Cymbalta - Lilly), a selective serotonin and norepinephrine reuptake inhibitor (SNRI), has been approved by the FDA for treatment of major depressive disorder in adults, and more recently for diabetic peripheral neuropathy as well. The Medical Letter will review its role in diabetic neuropathy in a future issue.

The fixed-dose combination of olanzapine and fluoxetine (Symbyax - Lilly) has been approved by the FDA for treatment of depressive episodes associated with bipolar disorder. Olanzapine alone (Zyprexa), which is mainly used as an antipsychotic (Medical Letter 2003; 45:102), is FDA-approved for treatment of acute manic episodes and for maintenance treatment of bipolar disorder. Fluoxetine alone (Prozac, and others), which is mainly used as an antidepressant (Medical Letter 2003; 45:93), has no specific approval for use in bipolar disorder.

Venlafaxine (Effexor, Effexor XR - Wyeth), an antidepressant that inhibits both norepinephrine and serotonin reuptake, was first approved by the FDA in 1993. It has been used mainly as a second-line agent for patients who have not responded to a selective serotonin reuptake inhibitor (SSRI). Some Medical Letter consultants have had the clinical impression that venlafaxine is more effective than an SSRI, particularly for patients with severe, classic depression (melancholia), and believe it should be considered a first-line drug (Treatment Guidelines from the Medical Letter 2003, 1:69). Is venlafaxine more effective than an SSRI for treatment of depression?

The ability of grapefruit juice to increase serum concentrations of drugs was first discovered during a study of the effect of ethanol on felodipine (Plendil) pharmacokinetics. Double-strength grapefruit juice used to disguise the taste of ethanol resulted in higher than expected serum concentrations of felodipine (DG Bailey et al, Clin Invest Med 1989; 12:357).

The latest definitions of overweight and obesity are based on body mass index (BMI). The BMI is calculated by dividing the weight in kilograms by the square of the height in meters (kg/m²). More than half of American adults are considered overweight with a BMI of ≥25, and about one third are obese with a BMI of ≥30. All ages seem to be affected; the proportion of children and adolescents who are overweight has more than doubled in the past 25 years. There is no lack of effort to treat obesity: drugs, diets and programs to change lifestyle are the basis for a large and flourishing industry. The frequent failure of diet and drug treatment sometimes leads to recommendations for surgery, usually restricted to those with a BMI ≥40.

Five different selective serotonin reuptake inhibitors (SSRIs) are promoted for treatment of depression and a sixth (fluvoxamine) for use in obsessive compulsive disorder. Which one should we prescribe for our patients?

In the February 2003 update of the Adverse Drug Interactions Program and in the Handbook of Adverse Drug Interactions 2003, the potentially lethal interaction between selective serotonin reuptake inhibitors (SSRIs) and monoamine oxidase inhibitors (MAOIs) was inadvertently omitted for citalopram (Celexa) and escitalopram (Lexapro). This interaction could occur with any SSRI.

A "Dear Colleague" letter from the UK's Committee on Safety of Medicines advised physicians, on the basis of unpublished data, not to use paroxetine (Paxil in the US; Seroxat in the UK) to treat children and adolescents with depression because of possible increased risk of suicidal behavior. This review describes the efficacy and safety of SSRIs in children.

The number of drugs marketed for psychiatric indications has increased sharply in recent years. The recommendations in this article are based on the results of controlled trials and on the experience and opinions of Medical Letter consultants. Interactions with other drugs can be found in The Medical Letter Handbook of Adverse Drug Interactions, 2003.

Changes caused by one drug in the absorption, distribution, metabolism or excretion of another may lead to a pharmacokinetic adverse drug interaction (DN Juurlink et al, JAMA 2003; 289:1652). Additive drug interactions, such as vasodilation caused by both sildenafil (Viagra) and nitrates, can also have adverse effects.

Aripiprazole (Abilify - Bristol-Myers Squibb/Otsuka), a quinolinone derivative, has been approved by the FDA for treatment of schizophrenia.

Atomoxetine (Strattera - Lilly) is the first non-stimulant drug to be approved by the FDA for treatment of attention deficit hyperactivity disorder (ADHD). Unlike other drugs approved for use in ADHD, it is not a controlled substance and is approved for use in adults as well as children. Older non-stimulant drugs that have been used to treat ADHD, although not FDA-approved, include the alpha₂-agonist clonidine (Catapres, and others) and the tricyclic antidepressant desipramine (Norpramin, and others) (Medical Letter 1996; 38:109).

Escitalopram (Lexapro - Forest), the active S-enantiomer of racemic citalopram (Celexa - Forest), a selective serotonin reuptake inhibitor (SSRI), was recently approved by the FDA for treatment of depression. The manufacturer plans to stop promoting Celexa in favor of Lexapro; Celexa will continue to be available for patients already taking it.

The FDA has approved a new formulation of fluoxetine for once-weekly maintenance treatment of depression in patients who have responded to daily fluoxetine (Prozac).

Rivastigmine tartrate (Exelon - Novartis), a carbamate-based cholinesterase inhibitor, is now being marketed for treatment of patients with dementia due to Alzheimer's disease.

Reports of adverse interactions between drugs continue to accumulate. Recently, the FDA has expanded the recommendations on drug interactions found in the package inserts of new drugs.

The number of drugs marketed for treatment of depression has increased in recent years. Antidepressants are generally also effective for treatment of anxiety.

Citalopram hydrobromide (Celexa - Forest/Parke-Davis), a selective serotonin reuptake inhibitor (SSRI) available in Europe since 1989, has now been approved by the US Food and Drug Administration (FDA) for treatment of depression. It is being advertised as having a 'favorable side-effect profile.'

Sibutramine hydrochlorid monohydreate (Meridia - Knoll), which is structurally related to amphetamine, has been approved by the FDA for treatment of obesity. It is classified by the Drug Enforcement Agency (DEA) as a schedule IV controlled substance.

Carvedilol (Coreg - SmithKline Beecham and Boehringer-Mannheim), a betaadrenergic and alpha-adrenergic blocker approved by the FDA for treatment of hypertension in 1995, but not marketed at that time, has now been approved and marketed for treatment of mild or moderate (NYHA class II or III) heart failure stabilized on other drugs. It is being promoted as an add-on drug that reduces the morbidity and mortality of the disease.

Bupropion hydrochloride, currently available as an antidepressant (Wellbutrin - Medical Letter, 31:97, 1989; Wellbutrin SR), is now being marketed in a sustainedrelease formulation as Zyban (Glaxo Wellcome) for use as an aid in smoking cessation.

The number of new drugs marketed for psychiatric indications has increased sharply in recent years. The recommendations in this article are based on the results of controlled trials and on the experience and opinions of Medical Letter consultants. Interactions with other drugs can be found in The Medical Letter Handbook of Adverse Drug Interactions, 1997.

Mirtazapine (mir taz a peen; Remeron - Organon) has been approved by the US Food and Drug Administration for treatment of depression. A tetracyclic piperazinoazepine, it is an analog of mianserin, an antidepressant available in Europe, but is structurally unrelated to antidepressants previously available in the USA.

Superseded by Drugs of Choice Handbook
Insomnia is a commom complaint, particularly among the elderly. Many drugs are approved by the US Food and Drug Administration (FDA) for treatment of insomnia, including five benzodiazepines and zolpidem (Ambien), a non-benzodiazepine that binds to benzodiazepine receptors in the brain. Some drugs marketed for other indications, such as antihistamines, antidepressants and antipsychotics, are also used as hypnotics. For many patients, nonpharmacological treatment of insomnia may be more effective than drugs, especially in the long term (CM Morin et al, Am J Psychiatry, 151:1172, 1994).

Nefazodone (Serzone - Bristol-Myers Squibb) was recently approved by the US Food and Drug Administration for treatment of depression. A phenylpiperazine, nefazodone is chemically related to trazodone (Desyrel, and others).

Drugs are used both to prevent and treat migraine symptoms. The effectiveness of such use can be difficult to evaluate, even with double-blind controlled trials, because migraine is episodic, response to placebo is frequent, and patients vary in response to a given agent (KMA Welch, N Engl J Med, 329:1476, 1993; SD Silberstein and RB Lipton, Neurology, 44 suppl 7:S6, Oct 1994).

Fluvoxamine (Luvox - Solvay), a selective serotonin reuptake inhibitor (SSRI), has been approved for treatment of obsessive-compulsive disorder (OCD) by the US Food and Drug Administration. Fluoxetine (Prozac), another SSRI antidepressant, and clomipramine (Anafranil), a tricyclic antidepressant that also inhibits serotonin reuptake, are the only other drugs available for this indication in the USA. Antidepressants that do not inhibit serotonin reuptake have not been effective for treatment of this condition.

A drug that combines the neutral sulfate salts of dextroamphetamine and racemic amphetamine with the dextro isomer of amphetamine saccharate and d,l amphetamine aspartate (Adderall - Richwood Pharmaceutical) has recently been promoted for treatment of children with Attention-Deficit/Hyperactivity Disorder (ADHD). This same mixture of amphetamine salts was previously marketed as Obetrol for treatment of obesity.

Venlafaxine hydrochloride (Effexor - Wyeth-Ayerst) was recently approved by the US Food and Drug Administration for treatment of depression. An aminomethyl-benzyl- cyclohexanol, it is chemically related to bupropion (Wellbutrin).

Approaches to treatment of Parkinson's disease have changed in recent years. Previously, the only goal was to treat symptoms with levodopa or other drugs. A new approach is to try to slow progression of the disease. (This issue is superseded by 1999 Drugs of Choice.)

Atovaquone (Mepron - Burroughs Wellcome), a hydroxynaphthoquinone, was recently approved by the US Food and Drug Administration (FDA) for oral treatment of mild to moderate Pneumocystis carinii pneumonia (PCP) in patients who cannot tolerate trimethoprim-sulfamethoxazole (Septra, Bactrim, and others). PCP is a common opportunistic infection and frequent cause of death in patients with AIDS.

Paroxetine (Paxil - SmithKline Beecham), a new selective serotonin reuptake inhibitor (SSRI), is now available in the USA. Two other SSRIs, fluoxetine (Prozac - Medical Letter, 30:45, 1988; 32:83, 1990) and sertraline (Zoloft - Medical Letter, 34:47, 1992), were approved previously.

Since the introduction of fluoxetine (Prozac - Medical Letter, 30:45, 1988), bupropion (Wellbutrin - Medical Letter, 31:97, 1989), sertraline (Zoloft - Medical Letter, 34:47, 1992) and paroxetine (Paxil - this issue), the choice of an antidepressant has become more difficult. Should these widely prescribed new drugs replace tricyclic antidepressants such as amitriptyline (Elavil, and others), imipramine (Tofranil, and others), or nortriptyline (Aventyl, and others) for treatment of most patients with depression?

Sertraline (Zoloft - Roerig), a serotonin reuptake inhibitor, was recently approved for marketing by the US Food and Drug Administration for treatment of depression. Another serotonin reuptake inhibitor, fluoxetine (Prozac), is prescribed more frequently in the USA than any other antidepressant (Medical Letter, 32:83, 1990).

Estazolam (ProSom - Abbott), a triazolobenzodiazepine derivative similar in structure to alprazolam (Xanax) and triazolam (Halcion), was recently marketed in the USA for treatment of insomnia.

Olsalazine sodium (Dipentum - Pharmacia), a dimer (two molecules linked by an azo bond) of 5-aminosalicylic acid, was recently approved by the US Food and Drug Administration for oral use to maintain remission of ulcerative colitis in adult patients who cannot tolerate sulfasalazine (Azulfidine; and others).

In the short time since fluoxetine (Prozac - Lilly) first became available in the USA (Medical Letter, 30:45, 1988), it has become the most frequently prescribed of all antidepressants. Some recent reports, however, have questioned its safety.

Bupropion (Wellbutrin - Burroughs Wellcome) was recently marketed in the USA for treatment of depression. First approved by the Food and Drug Administration in late 1985, the drug was withdrawn from the market in early 1986 because of a high incidence of seizures in one study.

Patients with Parkinson's disease have a deficiency of the neurotransmitter dopamine, a catecholamine. Dpamine itself cannot be used to treat the disease because it does not cross the blood-brain barrier, but its metabolic precursor, levodopa, does cross into the brain and is converted to dopamine by a decarboxylase present both in the brain and in the intestinal tract (JM Cedarbaum, Clin Pharmacokinet, 13:141, 1987).

Clomipramine (Anafranil - Ciba-Geigy), a tricyclic antidepressant, is now available for treatment of obsessive compulsive disorder (OCD) in accordance with the new US Food and Drug Administration (FDA) procedure for promising investigational drugs (FE Young et al, JAMA, 259:2267, 1988). In other countries, clomipramine has been widely used for many years for treatment of depression.

Fluoxetine (Prozac - Dista), a phenylpropylamide, is the first serotonin-reuptake blocker introduced in the USA for treatment of . It is being promoted as causing fewer adverse effects than other antidepressants. Claims of greater safety and patient tolerability have often been made for new non-tricyclic antidepressants in recent years, but unpredicted adverse effects have emerged with widespread use, including priapism with trazodone (Desyrel - Medical Letter, 26:35, 1984) and fatal hemolytic anemia with nomifensine (Merital - Medical Letter, 27:73, 1985).