Doxepin is an active ingredient that belongs to the tricyclic antidepressant group. It is mainly used to treat depression, but can also be used for anxiety and in addiction therapy. Taking it can cause side effects such as fatigue, dizziness, itching, and weight gain. Learn more about the effects, side effects, and dosage of doxepin here.
Antidepressant doxepin
Doxepin belongs to the group of tricyclic antidepressants, which also includes agents such as amitriptyline or opipramol. The active ingredient is not only used to treat depression, but can also help with anxiety and sleep disorders. In addition, it is used in addiction therapy, especially for opiate addicts. Doxepin has a depressant and mood-lifting effect. While the depressant effect usually sets in within an hour of taking it, the mood elevation often does not occur for two to three weeks. For this reason, patients with suicidal thoughts in particular must be closely monitored at the beginning of use. With regard to the depressant effect, it must be noted that this may diminish if the antidepressant is taken for a longer period of time.
Effect of doxepin
Doxepin increases the concentration of serotonin and norepinephrine in the brain by inhibiting the reuptake of the neurotransmitters into their stores. In addition, the drug blocks histamine receptors, thereby decreasing the effectiveness of the tissue hormone histamine. Similarly, doxepin lowers the effectiveness of the neurotransmitter acetylcholine. This can result in lower blood pressure and a slowed heartbeat, among other symptoms.
Side effects of doxepin
For example, at the beginning of treatment with doxepin, the following side effects may occur:
- Fatigue
- Drowsiness
- Dry mouth
- Dizziness
- Tremor
- Drop in blood pressure
- Cardiac arrhythmia
- Constipations
- Weight gain
Later, common side effects include allergic skin reactions and itching, sexual dysfunction, problems with urination, thirst and inner restlessness. Occasionally, there may also be disturbances in the conduction of excitation, circulatory problems, urinary retention, tissue insensations such as tingling, ringing in the ears and increased dreaming. Finally, very rare side effects of doxepin include breast enlargement (in both men and women), changes in blood sugar levels, hair loss, changes in blood counts, cardiac arrhythmias, and drug-dependent hepatitis.
Dose doxepin correctly
The active ingredient doxepin is available in various dosage forms, including tablets, coated tablets, capsules, drops, or injection solutions. The exact dosage in each case is determined individually by the treating physician. Therefore, please understand the following dosage information as general guidelines only. If doxepin is used to treat depression, only a small dose is usually prescribed at the beginning of the therapy. This is then gradually increased until the smallest effective dose is determined. Usually, 50 milligrams is started, after which the dose can be increased relatively quickly up to 150 milligrams. If the patient is hospitalized, up to 300 milligrams is possible. Older people are at increased risk for side effects. They should therefore take the antidepressant in as low a dose as possible. This also makes sense, since taking it can cause them to become confused.
Overdose is dangerous
If you overdose on doxepin, you should seek medical attention immediately because the overdose can potentially cause serious side effects. Depending on how high the dose taken was, you may experience cardiovascular and central nervous system disorders. This may cause confusion and seizures, and in severe cases, coma and respiratory failure. To avoid overdose, do not make up a forgotten dose. Instead, continue taking it as usual at the next time.
Discontinuing doxepin
Treatment with doxepin should never be stopped abruptly – especially if the drug has been taken for a long time and in high doses. Otherwise, side effects such as nausea, vomiting, restlessness, and sleep disturbances may occur.Always discuss with your treating physician the best way to proceed when stopping the active substance. The rule of thumb is to reduce the dose by no more than half each week.
Multiple drug interactions
If other antidepressants or medications for Parkinson’s disease are taken at the same time, this may increase the effect and side effects of doxepin. In addition, the depressant effect may be enhanced by neuroleptics, sedating antihistamines, antiepileptic drugs, analgesics, sleeping pills, sedatives, and the active ingredient cimetidine. Alcohol may also potentiate or alter doxepin effects. Drugs that lower potassium levels, block the breakdown of doxepin in the liver, or prolong the QT interval should also not be taken concomitantly with the antidepressant. The same applies to medications for high blood pressure (clonidine, reserpine). If doxepin is used concomitantly with H1 antihistamines, neuroleptics, antimalarials, antibiotics, neuroleptics, or antiarrhythmics, it may increase existing cardiac arrhythmias.
Interactions with MAO inhibitors
So-called MAO inhibitors, which are also used to treat depression, should generally not be taken concomitantly with doxepin. In general, therapy should be stopped at least two weeks before starting treatment with doxepin. Otherwise, severe side effects such as seizures, unconsciousness, high fever, and clouding of consciousness may occur. In individual cases of depression that is difficult to treat, the additional administration of MAO inhibitors is possible. In such cases, however, the patient must be carefully monitored by the attending physician. In addition, the dose of MAO inhibitors must be increased only slowly.
Contraindications
Doxepin must not be used if hypersensitivity to the active substance is present. In addition, the antidepressant must not be taken in:
- A paralysis-related intestinal obstruction
- Acute urinary retention
- Intoxication with sleeping pills and painkillers, as well as alcohol and psychotropic drugs.
- Acute delirium
- An enlargement of the prostate with residual urine formation
- A narrow-angle glaucoma
Only after a careful risk-benefit assessment should you take the drug in cases of severe liver damage, prostate enlargement without residual urine formation, slowed heartbeat, heart diseases such as QT syndrome, potassium deficiency, disorders of blood formation or increased tendency to convulsions. In general, the use of doxepin requires regular medical monitoring. Blood pressure, ECG, liver function and blood count must be checked. If values deviating from the norm are found, treatment may be continued only if the patient is checked at short intervals.
Pregnancy and lactation
Because there is insufficient experience to date for the use of doxepin during pregnancy, the antidepressant should be taken only when absolutely necessary. Beforehand, a careful risk-benefit assessment should be carried out by the doctor. This is because the newborn may experience withdrawal symptoms as a result of taking the drug. There may also be an increased risk of malformation. Doxepin must not be taken during breastfeeding, as the active substance can pass into breast milk. This may cause side effects in the infant. If treatment is absolutely necessary, breastfeeding should be stopped beforehand. Children under the age of twelve should not take the antidepressant, nor should nursing mothers. No studies are available on the effects of long-term use on growth, maturation and cognitive development in children and adolescents. Doxepin is also not usually used in adolescents up to 18 years of age, as the drug is unlikely to have any therapeutic benefit in them.
