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.

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 a low-dose formulation of the selective serotonin reuptake inhibitor (SSRI) paroxetine mesylate (Brisdelle – Noven Therapeutics) for treatment of moderate-to-severe vasomotor symptoms associated with menopause. It is the first non-hormonal therapy to be approved for this indication. Paroxetine mesylate (Pexeva) and paroxetine hydrochloride (Paxil, and generics) are marketed in higher doses for treatment of depression and other psychiatric disorders.

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) can be 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.

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.

The FDA has approved the marketing of iloperidone (Fanapt – Vanda), a second-generation antipsychotic, for treatment of schizophrenia. Iloperidone is chemically related to risperidone (Risperdal, and others).

Asenapine (Saphris - Schering-Plough), a dibenzo-oxepino pyrrole, has been approved by the FDA in a sublingual tablet formulation for acute treatment of schizophrenia and manic or mixed episodes associated with bipolar disorder. It is the sixth second-generation antipsychotic approved by the FDA for use in bipolar disorder.

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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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.

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.

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.

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.

Irritable bowel syndrome (IBS) is a common disorder, occuring in about 15% of the US population; it is 2-3 times more frequent in women than in men. IBS is characterized by chronic abdominal pain or discomfort and altered bowel habits.

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 recently cleared the AmpliChip CYP450 Test (Roche), which analyzes blood-derived DNA to detect genetic variations in the activity of cytochrome P450 (CYP) enzymes CYP2D6 and CYP2C19 and determines the metabolizer status of the patient. The test is intended to help guide clinicians in prescribing individualized drug therapy. About 25% of all drugs, including many antidepressants and antipsychotics, are substrates of either CYP2D6 or CYP2C19. The test is being promoted initially to psychiatrists.

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?

Breaking drug tablets in half is a common practice. In some cases, a lower drug dose may be as effective as a higher one, with fewer adverse effects. Sometimes tablets are split to achieve an intermediate dose between marketed strengths. When 2 tablet sizes cost the same, as they often do, splitting the larger size saves money. Is this a reasonable practice?

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.

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 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.

Fluoxetine, a selective serotonin reuptake inhibitor (SSRI) previously sold only as Prozac, is now also marketed as Sarafem for treatment of premenstrual dysphoric disorder (PMDD). Generic fluoxetine is expected to be available sometime this year.

Even though its effectiveness has not been established, many patients take St. John's Wort (Hypericum perforatum), an over-the-counter herbal extract, to treat symptoms of depression, often without the knowledge of their physicians. Recent reports indicate that St. John's wort interacts adversely with a number of 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.'

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.

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.

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).

Recent reports have suggested that some obese patients may benefit from long-term pharmacologic treatment (RL Atkinson and VS Hubbard, Am J Clin Nutr, 60:153, August 1994; DJ Goldstein and JH Potvin, Am J Clin Nutr, 60:647, November 1994). Fluoxetine (Prozac), widely used for treatment of depression and near approval by the US Food and Drug Administration (FDA) for treatment of bulimia, is also being tried 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).

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.