Phenelzine is a monoamine oxidase inhibitor (MAO inhibitor) used in therapy of severe depression. Phenelzine therapy is associated with rare instances of clinically apparent acute liver injury. Phenelzine is a Monoamine Oxidase Inhibitor. The mechanism of action of phenelzine is as a Monoamine Oxidase Inhibitor.
Phenelzine is a non-selective and irreversible monoamine oxidase inhibitor (MAOI) of the hydrazine class which is used as an antidepressant and anxiolytic. It is a monoamine oxidase inhibiting antidepressant that is effective in the treatment of panic disorder and social anxiety disorder. Along with tranylcypromine and isocarboxazid, phenelzine is one of the few non-selective and irreversible MAOIs still in widespread clinical use. It is typically available in 15 mg tablets and doses usually range from 30–90 mg per day, with 15 mg every day or every other day suggested as a maintenance dose following a successful course of treatment.
Mechanism of Action of Phenelzine
The basic mechanism of action of phenelzine acts as an inhibitor and substrate of monoamine oxidase which subsequently causes an elevation in brain levels of catecholamines and serotonin. It also presents a similar structure to amphetamine which explains the effect on the uptake and release of dopamine, noradrenaline, and serotonin. Phenelzine has been reported to inhibit tyrosine aminotransferase, aromatic amino acid decarboxylase, and dopamine B-hydroxylase.
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The antidepressant phenelzine is a monoamine oxidase inhibitor known to inhibit various other enzymes, among them semicarbazide-sensitive amine oxidase (currently named primary amine oxidase: SSAO/PrAO), absent from neurons but abundant in adipocytes. It has been reported that phenelzine inhibits adipocyte differentiation of cultured preadipocytes. To further explore the involved mechanisms, our aim was to study in vitro the acute effects of phenelzine on de novo lipogenesis in mature fat cells. Therefore, glucose uptake and incorporation into lipid were measured in mouse adipocytes in response to phenelzine, other hydrazine-based SSAO/PrAO-inhibitors, and reference agents. None of the inhibitors was able to impair the sevenfold activation of 2-deoxyglucose uptake induced by insulin. Phenelzine did not hamper the effect of lower doses of insulin. However, insulin-stimulated glucose incorporation into lipids was dose-dependently inhibited by phenelzine and pentamidine, but not by semicarbazide or BTT2052. In contrast, all these SSAO/PrAO inhibitors abolished the transport and lipogenesis stimulation induced by benzylamine. These data indicate that phenelzine does not inhibit glucose transport, the first step of lipogenesis, but inhibits at 100 uM the intracellular triacylglycerol assembly, consistently with its long-term anti-adipogenic effect and such rapid action was not found with all the hydrazine derivatives tested. Therefore, the alterations of body weight control consecutive to the use of this antidepressant drug might be not only related to central effects on food intake/energy expenditure but could also depend on its direct action in adipocytes. Nonetheless, phenelzine antilipogenic action is not merely dependent on SSAO/PrAO inhibition
Indications of Phenelzine
- Migraine prevention
- Depression
- Exogenous depression
- Neurotic depression
- Atypical Depressive disorder
Contra-Indications of Phenelzine
- Pheochromocytoma
- Overactive thyroid gland
- Diabetes
- Low blood sugar
- Schizophrenia
- Manic-Depression
- Having Thoughts of Suicide
- High blood pressure
- Extremely high blood pressure
- Angina
- Coronary artery disease
- Abnormal heart rhythm
- Chronic heart failure
- Disease of the heart and blood vessels
- Disorder of the blood vessels of the brain
- Blood Pressure drop upon standing
- Abnormally low blood pressure
- Kidney disease with the reduction in kidney function
- Method of X-Raying the spinal canal using dye
- Seizures
- A severe Headache
- Frequent Headaches
- Abnormal liver function tests
Side Effects of Phenelzine
The most common
- a severe headache, rapid heartbeat, stiffness in your neck,
- chest pain, fast or slow heart rate;
- swelling, rapid weight gain;
- Xerostomia (dry mouth)
- A headache
- Fatigue
- Skin reactions
- Hypotension
- Anxiety
- Constipation
- Nausea/vomiting
- Weight gain/loss
- Erectile dysfunction
More common
- Abdominal or stomach pain, discomfort, or tenderness
- chills or fever
- difficulty with moving
- headache, severe and throbbing
- joint or back pain
- muscle aching or cramping
- muscle pains or stiffness
- chest pressure or squeezing pain in chest
- discomfort in arms, shoulders, neck or upper back
- excessive sweating
- feeling of heaviness, pain, warmth and/or swelling in a leg or in the pelvis
- sudden tingling or coldness in an arm or leg
- sudden slow or difficult speech
- sudden drowsiness or need to sleep
- fast breathing
- sharp pain when taking a deep breath
- fast or slow heartbeat
- coughing up blood
- rust colored urine
- decreased amount of urine
Rare
- Anxiety
- change in vision
- chest pain or tightness
- confusion
- cough
- Agitation
- arm, back, or jaw pain
- blurred vision
- chest pain or discomfort
- convulsions
- extra heartbeats
- fainting
- hallucinations
- headache
- irritability
- lightheadedness
- mood or mental changes
- muscle pain or cramps
- muscle spasm or jerking of all extremities
- nervousness
Drug Interactions of Phenelzine
Phenelzine may interact with following drug, supplements, & may change the efficacy of the drug
- alpha agonists (e.g., clonidine, methyldopa)
- amphetamines (e.g., dextroamphetamine, lisdexamphetamine)
- angiotensin-converting enzyme inhibitors (ACEIs; captopril, enalapril, ramipril)
- angiotensin receptor blockers (ARBs; e.g., candasartan, irbesartan, losartan)
- antihistamines (e.g,. cetirizine, doxylamine, diphenhydramine, hydroxyzine, loratadine)
- antipsychotics (e.g., chlorpromazine, clozapine, haloperidol, olanzapine, quetiapine, risperidone)
- levodopa
- beta-agonists (e.g., formoterol, salbutamol, salmeterol)
- other beta-blockers (e.g., propanolol, metoprolol)
- calcium channel blockers (e.g., amlodipine, diltiazem, nifedipine, verapamil)
- carbamazepine
- ceritinib
- crizotinib
- cyclosporine
- dexamethasone
- diuretics (water pills; e.g., furosemide, hydrochlorothiazide)
- duloxetine
- lapatinib
- levodopa
- tramadol
- lidocaine
- macrolide antibiotics (e.g., azithromycin, clarithromycin, erythromycin)
- nilotinib
- nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., ibuprofen, naproxen)
- pentoxifylline
- phosphodiesterase-5-inhibitors (e.g., sildenafil, tadalafil)
- selective serotonin reuptake inhibitors (SSRI; e.g., fluoxetine, paroxetine, sertraline)
- tricyclic antidepressants (e.g., amitriptyline, doxepin, nortriptyline)
Pregnancy Catagory
FDA Pregnancy Category C
Pregnancy
This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.
Lactation
It is not known if phenelzine passes into breast milk. If you are a breastfeeding mother and are taking this medication, it may affect your baby. Do not breast-feed while you are taking this medication. The safety and effectiveness of using this medication have not been established for children less than 16 years old.
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