Nortriptyline is a medication classified as a tricyclic antidepressant (TCA). Its primary, FDA-approved function is the treatment of major depressive disorder. Beyond this intended purpose, nortriptyline is frequently prescribed for off-label uses, including the management of chronic insomnia. This application leverages one of the drug’s secondary effects to aid individuals who struggle with sleep.
How Nortriptyline Aids Sleep
The sleep-promoting effects of nortriptyline stem from a different biological pathway than its antidepressant properties. While it elevates mood by inhibiting the reuptake of neurotransmitters like norepinephrine, its sedative quality is due to its potent antihistamine effects. Nortriptyline acts as an antagonist at the H1 histamine receptor, blocking the action of histamine, a chemical that promotes wakefulness. This action, similar to many over-the-counter sleep aids, is what allows nortriptyline to induce drowsiness and help maintain sleep, separate from its antidepressant function.
Recommended Dosage for Insomnia
When prescribed for insomnia, nortriptyline is initiated at a low dose, between 10 mg and 25 mg per day. The medication is available in 10 mg, 25 mg, and 50 mg tablets for adjustments. This contrasts sharply with the dosages used to treat depression, which range from 75 mg to 150 mg daily. The lower amount for sleep leverages the sedative side effect rather than a full antidepressant response, and the optimal dose is determined by a medical professional based on the patient’s needs.
The dose is taken once daily, about 30 to 60 minutes before bedtime. This timing allows the medication’s sedative effects to coincide with when the person intends to fall asleep. Taking it too close to morning may result in next-day grogginess. Regular follow-up with a healthcare provider is important to monitor effectiveness and manage potential side effects.
Side Effects and Safety Considerations
At low doses for insomnia, common side effects include next-day drowsiness or a “hangover effect,” dry mouth, constipation, and mild dizziness. These effects are often mild and may decrease as the body adjusts. To manage dry mouth, chewing sugar-free gum or drinking water is helpful. To avoid dizziness, stand up slowly from a sitting or lying position.
While the risk of serious side effects is lower with these doses, it is not eliminated. Potential cardiac issues, like an irregular or fast heartbeat, can occur, and the medication should be used cautiously in patients with pre-existing heart conditions. Nortriptyline is contraindicated for individuals recovering from a heart attack. Avoid combining it with alcohol, as this can increase drowsiness and impair coordination.
Special caution is advised for older adults, who may be more sensitive to the medication’s effects and at a higher risk for confusion, falls, and other complications. The dosage for elderly patients is often started and maintained at a lower level to minimize these risks. The use of nortriptyline is also contraindicated with monoamine oxidase inhibitors (MAOIs), requiring at least a 14-day gap between stopping one and starting the other to prevent a dangerous interaction.