Drug update: New antidepressants--beyond SSRIs. (Primary Care).
Because the SSRIs--citalopram, fluoxetine, fluvoxamine, paroxetine, and sertraline--have a longer track record, most experts continue to use them as first-line agents for treating depression. But the newer drugs listed here are generally ranked as comparable to the SSRIs in all other respects.
How would you choose among them? If a patient has been treated successfully in the past, use the same agent. Otherwise, there is no evidence-based way to decide which drug is best for an individual patient.
Some experts recommend matching a patient's symptom complex to the drug's spectrum of effects: for example, using a more sedating agent for a patient whose depression is accompanied by pronounced anxiety. But even this approach has not been supported by study results.
The most significant recent trend in treating depression is to maximize the dosage of whichever drug is used first before switching to a different drug. Also, treatment with the first drug is maintained for up to 12 weeks before it is deemed ineffective and the patient is switched to another drug; in the past, experts recommended sticking with an ineffective drug for only 6 weeks before trying something new The goal of treatment is full remission of symptoms; partial remission is considered inadequate and a reason to switch drugs. When this occurs, some authorities favor picking an agent from a different class, more because it seems sensible than because of any evidence. Others recommend adding lithium or thyroid hormone.
Once remission occurs, treatment should continue for at least 6-9 months. Patients with multiple episodes of depression are likely to require treatment for at least 2 years, and possibly indefinitely.
With depression increasingly viewed as a chronic illness, issues of cost assume more prominence. Fluoxetine is now available in a generic formulation.
All four listed drugs should be used cautiously during pregnancy, in women who are breast-feeding, and in elderly patients. All of the drugs listed here are rated pregnancy category C except bupropion, which is category B. Nefazodone should be started at half the usual dose in the elderly; all others should be started at a low dose and gradually titrated to the most effective dose.
Drug Dosage Cost/Day venlafaxine 75-225 mg/day $2.61 (Effexor, (Effexor-XR) (150 mg) (*) Effexor-XR) mirtazapine 15-45 mg/day $2.61 (Remeron) (30 mg) (*) nefazodone 300-600 mg/day $2.70 (Serzone) (500 mg) (**) bupropion 300-450 mg/day $4.48 (Wellbutrin, (Wellbutrin) (400 mg) (*) Wellbutrin SR) Drug Comment (+) venlafaxine Serotonin-norepinephrine reuptake inhibitor. Strongly (Effexor, inhibits norepinephrine and 5-hydroxytryptamine (5-HT) Effexor-XR) reuptake and weakly inhibits dopamine reuptake. Most commonly used as a second-line agent or in patients with generalized anxiety disorder accompanying depression. Treatment is associated with increases in blood pressure, so avoid in patients with uncontrolled hypertension. Nausea is the most frequently reported adverse effect. Contraindicated for patients on a monoamine oxidase (MAO) inhibitor or within 14 days of treatment with an MAO inhibitor. The extended-release formulation generally is preferred. The conventional-release formulation is used at a dosage of 75-350 mg/day. mirtazapine Not a reuptake inhibitor; appears to enhance central (Remeron) noradrenergic and serotonergic activity. The drug is associated with significant somnolent effects in some patients. Weight gain and dry mouth also have been reported frequently. Contraindicated for patients on an MAO inhibitor or within 14 days of treatment with an MAO inhibitor. nefazodone This 5-[HT.sub.2] antagonist and reuptake inhibitor (Serzone) also exhibits [[alpha].sub.1]-adrenergic blocking activity. While it has become a common choice for patients with anxiety symptoms because of its somnolent effects, it is associated with more drug-drug interactions than are the SSRIs and other post-SSRI antidepressants. Contraindicated for patients on an MAO inhibitor or within 14 days of treatment with an MAO inhibitor. Start at half the usual dosage in elderly patients and titrate up to the full adult dosage. bupropion This dopamine reuptake inhibitor exhibits minimal (Wellbutrin, effects on norepinephrine or 5-HT reuptake. A Wellbutrin SR) popular second-line agent; also seems to be associated with less sexual dysfunction than are some SSRIs. Associated with an increased risk of seizures with total daily dosages greater than 450 mg; there are also case reports of hyponatremia, extrapyramidal effects, and parkinsonism with such higher doses. Bupropion has been reported to interact with anticonvulsants and imipramine and to cause panic attacks when used in combination with the SSRI paroxetine. Contraindicated for patients with seizure disorders or a history of bulimia or anorexia nervosa. Contraindicated for patients on an MAO inhibitor or within 14 days of treatment with an MAO inhibitor. Use cautiously in elderly patients and those with reduced renal function. Bupropion is also marketed as an aid to smoking cessation under the name Zyban. Available in a sustained-release formulation; dosage of SR formulation is 300-400 mg/day. (*)Cost/day is based on the average wholesale price for a 100-unit container of the indicated drug in the 2001 Red Book. (**)Cost/day is based on the average wholesale price for a 60-unit container of the indicated drug in the 2001 Red Book. (+)The comments reflect the viewpoints and expertise of the following sources: Dr. Gregory E. Simon, investigator, Center for Health Studies, Group Health Cooperative, Seattle. Dr. Madhukar H. Trivedi, associate professor of psychiatry and director of the depression and anxiety disorders program, University of Texas Southwestern Medical Center at Dallas. Dr. John W. Williams, associate professor of medicine, Duke University Medical Center, Durham, N.C.
|Printer friendly Cite/link Email Feedback|
|Publication:||OB GYN News|
|Date:||Mar 1, 2002|
|Previous Article:||Adverse events seen with ginseng combinations. (Postmenopausal Bleeding, Agranulocytosis).|
|Next Article:||High fish consumption key route to heart health. (Several Studies Support Fish Oil Effect).|