Phenelzine

Phenelzine is a prescription medication used to treat depression. Because of its potentially serious side effects, it is often used only after other antidepressants haven't worked. Phenelzine belongs to a group of drugs called monoamine oxidase (MAO) inhibitors. It works by increasing the levels of certain natural chemicals in the brain that affect your mood and help maintain mental balance.

Phenelzine comes in tablet form. It is usually taken 3 times daily, with or without food.

Common side effects include dizziness, headache, and insomnia. Phenelzine can cause drowsiness. Do not drive or operate heavy machinery until you know how it affects you.

Phenelzine is a prescription medication used to treat depression, when other medications have failed.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Take phenelzine exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.

The phenelzine dose your doctor recommends will be based on the following:

• other medical conditions you have
• other medications you are taking
• how you respond to this medication 

The usual starting dose of phenelzine is one tablet (15 mg) three times a day.

Dosage should be increased to at least 60 mg per day. After maximum benefit from phenelzine is achieved, dosage should be reduced slowly over several weeks. Maintenance dose may be as low as one tablet, 15 mg, a day or every other day, and should be continued for as long as is required.

Suicidality and Antidepressant Drugs

Antidepressants increased the risk compared to placebo of suicidal thinking and behavior (suicidality) in children, adolescents, and young adults in short-term studies of major depressive disorder (MDD) and other psychiatric disorders. Anyone considering the use of phenelzine or any other antidepressant in a child, adolescent, or young adult must balance this risk with the clinical need. Short-term studies did not show an increase in the risk of suicidality with antidepressants compared to placebo in adults beyond age 24; there was a reduction in risk with antidepressants compared to placebo in adults aged 65 and older. Depression and certain other psychiatric disorders are themselves associated with increases in the risk of suicide. Patients of all ages who are started on antidepressant therapy should be monitored appropriately and observed closely for clinical worsening, suicidality, or unusual changes in behavior. Families and caregivers should be advised of the need for close observation and communication with the prescriber. phenelzine is not approved for use in pediatric patients.

Serious side effects have been reported with phenelzine including:

• hypertensive crisis, a life threatening increase in blood pressure. This sometimes fatal side effect can result from taking MAO inhibitors like phenelzine with certain drugs and foods (see "Drug Interactions" and "Food Interactions" sections). Symptoms include:
  • headaches
  • stiff or sore neck
  • nausea
  • vomiting
  • palpitations
  • sweating, sometimes with fever and cold, clammy skin
  • either fast or slow heart beat
  • chest pain
  • chest tightness
  • dilated pupils

Get medical help right away if you experience these symptoms.

• severe headaches. If you have frequent headaches, talk to your doctor before starting phenelzine as headaches are one of the first symptoms of a hypertensive crisis and you may miss this warning sign.
• suicidal thoughts or behavior. Antidepressants may increase suicidal thoughts or actions in some children, teenagers, and young adults within the first few months of treatment.
  • Pay close attention to any changes, especially sudden changes, in mood, behaviors, thoughts, or feelings. This is very important when an antidepressant medicine is started or when the dose is changed.
  • Call the healthcare provider right away to report new or sudden changes in mood, behavior, thoughts, or feelings.
• low blood pressure, especially when getting up from a lying position.

Phenelzine can cause drowsiness. Do not drive or operate heavy machinery until you know how it affects you.

Do not take phenelzine if you:

• are allergic to any ingredient in phenelzine
• have a type of adrenal tumor known as pheochromocytoma
• have congestive heart failure
• have severe kidney disease
• have a history of liver disease
• a type of adrenal tumor known as pheochromocytoma

Serious side effects have been reported. See "Drug Precautions" section.

Common side effects include:

• dry mouth
• dizziness
• headaches
• weight gain
• nausea
• constipation
• decreased sexual ability
• insomnia
• drowsiness
• weakness
• low blood pressure when standing or sitting up
• muscle twitches or shakiness

This is not a complete list of phenelzine side effects. Ask your doctor or pharmacist for more information.

Tell your doctor about all of the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

• certain other antidepressants including amitriptyline (Elavil), amoxapine, clomipramine (Anafranil), desipramine (Norpramin), doxepin (Sinequan), imipramine (Tofranil), maprotiline, mirtazapine (Remeron), nortriptyline (Pamelor), protriptyline (Vivactil), and trimipramine (Surmontil)
• amphetamines such as amphetamine (in Adderall), benzphetamine (Didrex), dextroamphetamine (Dexedrine, Dextrostat, in Adderall), and methamphetamine (Desoxyn)
• barbiturates such as pentobarbital (Nembutal), phenobarbital (Luminal), and secobarbital (Seconal)
• beta blockers such as atenolol (Tenormin), labetalol (Normodyne), metoprolol (Lopressor, Toprol XL), nadolol (Corgard), and propranolol (Inderal)
• bupropion (Wellbutrin, Zyban)
• buspirone (BuSpar)
• caffeine (No-Doz, Quick-Pep, Vivarin)
• cyclobenzaprine (Flexeril)
• dexfenfluramine (Redux) (not available in the U.S.)
• dextromethorphan (Robitussin, others)
• doxepin cream (Zonelon)
• duloxetine (Cymbalta)
• epinephrine (Epipen, Primatene Mist)
• guanethidine (Ismelin) (not available in the U.S.)
• insulin and oral medications for diabetes
• levodopa (Larodopa, in Sinemet)
• medications for allergies, cough and cold symptoms, hay fever; anxiety, sinus problems, or weight loss (diet pills, appetite suppressants)
• medication for high blood pressure including diuretics ('water pills'), and reserpine (Serpalan)
• medications for seizures such as carbamazepine (Tegretol)
• narcotic medications for pain
• nasal decongestants, including nose drops and sprays
• other MAOIs such as isocarboxazid (Marplan), pargyline (not available in the U.S.), procarbazine (Matulane), tranylcypromine (Parnate), and selegiline (Eldepryl, Emsam, Zelapar)
• meperidine (Demerol)
• methyldopa (Aldomet)
• sedatives
• selective serotonin reuptake inhibitors such as citalopram (Celexa), escitalopram (Lexapro), fluoxetine (Prozac), fluvoxamine (Luvox), paroxetine (Paxil), and sertraline (Zoloft)
• sleeping pills
• tranquilizers
• venlafaxine (Effexor)
• medications containing alcohol (Nyquil, elixirs, others)

This is not a complete list of phenelzine drug interactions. Ask your doctor or pharmacist for more information.

Phenelzine can remain in your body for several weeks after you stop taking it. Tell your doctor or pharmacist that you recently stopped taking phenelzine before you start taking any new medications.

Tell your doctor if you are pregnant or plan to become pregnant. It is not known if phenelzine will harm your unborn baby.

Tell your doctor if you are breastfeeding or plan to breastfeed. It is not known if phenelzine is excreted in human breast milk or if it will harm your nursing baby.

Phenelzine can cause a life threatening increase in blood pressure. Avoid eating very large amounts of foods containing high amounts of tyramine. Tyramine may cause dangerously high blood pressure in people taking phenelzine.

Phenelzine may increase suicidal thoughts or actions in some children, teenagers, and young adults within the first few months of treatment.

• Pay close attention to any changes, especially sudden changes, in mood, behaviors, thoughts, or feelings. This is very important when an antidepressant medicine is started or when the dose is changed.

Phenelzine can be taken with or without food. If phenelzine upsets your stomach, try taking it with food.