Active substance



Doxepin (trade name: Aponal®) is a drug from the group of tricyclic antidepressants. It acts in the central nervous system by inhibiting the reuptake of the neurotransmitters serotonin and noradrenalin. Doxepin has a mood-lifting and sedative (attenuating) effect.

The main indication (area of application) is depression. While the damping effect starts soon after the start of the intake, it takes about 2-3 weeks until the mood-lifting effect starts. This course is typical for antidepressants.

Side effects

Tricyclic antidepressants have an anticholinergic effect in common. This means that they block certain receptors (cholinergic receptors) and thus cause certain side effects. The typical anticholinergic side effects include Other possible side effects of Doxepin are In rare cases, blood count changes may occur.

In addition, the risk of epileptic seizures may increase in people with a history of epilepsy (lowering of the seizure threshold). Occasionally, the syndrome of inadequate ADH secretion (SIADH or Schwartz-Bartter syndrome) may occur, which is manifested among other things in changes in the composition of blood salts (electrolytes) with corresponding symptoms. – Dry mouth

  • Constipation (constipation)
  • Problems urinating (urination problems)
  • Tachycardia
  • Difficulties in focusing with the eyes (accommodation disorders)
  • An increase in intraocular pressure (especially to be observed in patients with glaucoma) and
  • States of confusion with clouding of consciousness (delirium). – Cardiac arrhythmia
  • Drop in blood pressure (hypotension)
  • Gastrointestinal complaints such as nausea and stomach pain
  • Skin rash (exanthema) and itching
  • Appetite and weight gain
  • Increased sweating (Hyperhidrosis)
  • Tiredness
  • Increase in liver values (transaminases) in the blood and
  • Sexual dysfunctions such as reduced sexual interest (decrease in libido) or potency disorders


A combination with other damping (sedating) agents should be avoided or handled with care, as this increases the damping effect and, if necessary, inhibits the respiratory drive (respiratory depressive effect). These include alcohol, older medicines for hay fever and other allergies (antihistamines), tranquillisers such as benzodiazepines (e.g. Valium®), sleeping pills, certain painkillers (opioids), medicines to treat psychosis (neuroleptics) and those used to treat epilepsy (antiepileptics). Combination with other drugs that also have an anticholinergic effect (i.e. they inhibit the acetylcholine receptor) should be handled with caution because of the possible increase in side effects.

These include, for example, other drugs for depression from the group of tricyclic antidepressants, atropine (Dysurgal®) and certain Parkinson’s drugs (e.g. Biperiden = Akineton ®). A combination with MAO inhibitors, which are also used to treat depression, should be avoided as there is a risk of serious side effects. These include states of agitation and confusion with clouding of consciousness, seizures and fever.

A combination of these symptoms is called serotonin syndrome or serotonergic syndrome. It is life-threatening and requires immediate discontinuation of the medication that is causing it as well as medical treatment and monitoring. Treatment with Aponal® can reduce the effect of certain blood pressure-lowering drugs.

These include clonidine (e.g. Catapresan ®) and methyldopa (e.g. Presinol®), which is used primarily during pregnancy. However, an increased reduction in blood pressure can also occur when combined treatment with, for example, beta-blockers (e.g. Beloc Zok ® and nitrates (e.g. Nitrangin®) is used. A combination with drugs for the treatment of cardiac arrhythmia (antiarrhythmic drugs) such as amiodarone and quinidine can increase the risk of cardiac arrhythmia.