Pamelor (nortriptyline) is a second-generation tricyclic antidepressant (TCA). TCAs are named for their three-ringed chemical structure. Pamelor is used in the treatment of major depression and childhood nocturnal enuresis (bedwetting). It is also used for chronic illnesses such as chronic fatigue syndrome, chronic pain, migraine, and labile affect in some neurological conditions. However, the use of tricyclic antidepressants has greatly decreased due to the development of selective serotonin reuptake inhibitors (SSRIs).
- How Does Pamelor Work?
- Dosage FAQs
- Possible Side Effects
- Drug Interactions of Pamelor
- Precautions and Warnings
- How to Safely Withdraw
How Does Pamelor Work?
Pamelor inhibits the reuptake of the neurotransmitter serotonin at the neuronal membrane or acts at beta-adrenergic receptors. This drug does not inhibit monoamine oxidase nor does it affect dopamine reuptake.
Pamelor, the N-demethylated active metabolite of amitriptyline, is a dibenzocycloheptene-derivative tricyclic antidepressant. TCAs are similar in structure to phenothiazines.
- What is a normal dose of this medication?
- Depression: Depending on your doctor’s guidance, 25 mg to 150 mg per day should be taken orally in divided doses or as a single dose at bed time. In people over the age of 65, the dose can range between 10 mg to 75 mg per day, in divided doses or as a single dose at bedtime.
- Nocturnal enuresis: Although this drug is not recommended for children under the age of 13, it may be prescribed for excessive bedwetting in some cases by your doctor. In general, the recommended dose for children under 13 will be between 10 mg and 35 mg per day, depending on the child’s body weight.
- Is it safe to use this drug if I am pregnant or become pregnant?
Although no conclusive studies have been performed on human pregnancies, all risks should be thoroughly weighed against their potential benefits when prescribing this drug to those who become pregnant or those who are pregnant. Small amounts of nortriptyline may be excreted into a nursing mother’s breast milk. The American Academy of Pediatrics classifies it as a drug whose effect is unknown, but may be of concern.
Find a Therapist
Depression, one of the conditions for which this drug is primarily prescribed, has also shown positive results for many when treated with psychotherapy. While this drug may help dull or remove some of the debilitating symptoms of depression, it cannot teach you more about what you are experiencing or help you develop healthy coping strategies should symptoms arise or become triggered. For a better, longer-lasting mental health outcome, consider finding a therapist or counselor to complement your treatment with medication.
- How is this drug processed in my body?
Pamelor is well-absorbed in the gastrointestinal tract. About 45% of this medication is metabolized in the liver and it has a half-life of 36 hours. 65% of this drug is excreted in an individual’s urine.
- What are some off-label uses for this drug?
Off-label use refers to conditions for which a doctor might prescribe this medication that are not part of the U.S. Food and Drug Administration (FDA) approved packaging label. This is a normal practice and for this medication includes the following applications:
- Chronic urticaria (chronic hives)
- Nocturnal pruritus (nighttime itch)
- Angioedema (rapid swelling of the skin)
- Smoking cessation
- Attention-deficit hyperactivity (ADHD)
- Postherpetic neuralgia
Possible Side Effects
If you experience any side effects from taking Pamelor, inform your doctor. Your dosage may need adjusted or alternative treatment may be better for your situation. Possible side effects include:
- Swollen face, lips, tongue, or throat
- Blurry vision
- Tunnel vision
- Swelling or pain in the eyes
- Abnormal movements of the eyes, jaws, or tongue
- Rapid heart rate
- Body numbness
- Stomach cramps
- Changes in appetite
- Urinary retention
An allergy to Pamelor may cause difficulty breathing.
Drug Interactions of Pamelor
Like other tricyclic antidepressants, Pamelor may interact with a wide range of substances. Some common drug interactions include:
- Tramadol: This drug increases the risk of serotonin syndrome and seizures when combined with Pamelor.
- Tranylcypromine: There is an increased risk of serotonin syndrome occurring with concurrent use. There should be a significant gap between therapies if this drug has been used by a person in treatment.
- Alcohol: Alcohol can increase the sedative effects of this medication
- Cimetidine. Clonidine, Diltiazem, Rifampicin, Fluconazole, and Fluoxetine: These drugs can inhibit the metabolism of Pamelor by inhibiting the hepatic (liver) enzymes.
- Nabilone: Concurrent use of Pamelor with nabilone may increase the efficacy of nabilone. Concurrent use may require a dosage adjustment.
- Salbutamol: Pamelor increases the sympathomimetic effect of salbutamol, causing a severe, unsafe increase in heart rate.
- Phenobarbitone: Concurrent administration may cause excessive sedation.
- Phenytoin: Concurrent use decreases the elimination of the drug from the body.
- Rasagiline: Concurrent use of this medication increases the risk of developing serotonin syndrome.
Precautions and Warnings
People experiencing major depression, both adult and pediatric, may experience worsening of their depression and/or an increase in suicidal behavior and thoughts. If you notice any drastic changes in your mood or increased feelings of suicidal ideation, please contact your doctor right away.
A potentially life-threatening condition called serotonin syndrome may develop, especially if this drug is combined with other drugs (such as other antidepressants) that increase the amount of serotonin in the body. Symptoms of this condition include increased agitation, hallucinations, fever, irregular heartbeat, overactive reflexes, nausea, vomiting, diarrhea, and fainting.
How to Safely Withdraw
Do not stop taking this drug suddenly. If you need to stop your treatment with Pamelor, it’s best to work out a safe plan with your doctor to reduce the occurrence and severity of withdrawal symptoms as your body may have become accustomed to having certain levels of this drug in your system. Withdrawal symptoms may include:
- Flu-like symptoms including fever, sore muscles, nausea, and vomiting
- Persistent headaches
- Holma, K.M. et al. (2008). Long-term outcome of major depressive disorder in psychiatric patients is variable. Journal of Clinical Psychiatry, 69(2), 196.
- Jann, M.W. and Slade, J.H. (2007). Antidepressant agents for the treatment of chronic pain and depression. Pharmacotherapy, 27(11), 1571.
- Kalia, M. (2005). Neurobiological basis of depression: An update. Metabolism, 54(5 Suppl 1), 24.
- Katz, L.Y. et al. (2008). Effect of regulatory warnings on antidepressant prescription rates, use of health services and outcomes among children, adolescents and young adults. Canadian Medical Association Journal, 178(8), 1005.
Page content reviewed by James Pendleton, ND.