Doxylamine (medication): Uses, Indications And Side Effects
Doxylamine is a medication that is primarily used to treat the symptoms of insomnia in the short term, since it facilitates sleep and improves it. It is an antihistamine drug (which blocks H1 histamine receptors).
For its part, histamine is related to allergic symptoms. In this article we will learn what doxylamine consists of, what are its general characteristics, indications, side effects, precautions, etc. In addition, we will also talk about insomnia.
Doxylamine is an antihistamine drug Specifically, it belongs to the group of H1 antihistamines. Its main indication is the short-term treatment of insomnia. However, it also has other uses, such as treating coughs and colds (it is usually combined with decongestants).
In its commercial format, it is common to find it in sachet format (in powders that dissolve in water). We can also find it in compressed format. All of this is orally.
What doxylamine, as well as other antihistamines in its group (H1), does is cross the blood-brain barrier. Afterwards, it causes drowsiness in the individual, since it inhibits the H1 receptors responsible for stimulating wakefulness. That is why it is effective in treating insomnia. Doxylamine can be purchased in pharmacies, and in Spain a medical prescription is not necessary.
Mechanism of action
Doxylamine is an antihistamine; It is derived from ethanolamine, an organic chemical compound. Its activity is based on a competitive, reversible and non-specific antagonistic action of histamine H1 receptors
Thus, doxylamine, as an antihistamine, acts by blocking the action of histamine; Histamine is a substance in the body that causes allergy symptoms. Specifically, histamine is found naturally in the cells of our immune system (mainly in mast cells and basophils).
Because histamine causes allergy symptoms, antihistamines are prescribed to relieve its symptoms (because they block its action). Doxylamine is effective in reducing the time a person falls asleep; In addition, it increases the depth and duration of sleep.
Pharmacokinetics
Let us remember that pharmacokinetics is a branch of pharmacology, responsible for studying the processes to which a drug is subjected when it is introduced and distributed throughout the body. It has to do with the metabolism of drugs, their half-life, excretion…
In the case of doxylamine, we know that its metabolism is hepatic (liver). Its half-life is 6 to 12 hours (the half-life of a drug is the length of time it takes for it to be reduced by half within the body). Its excretion is 60% in urine and 40% in feces
Administration mode
Doxylamine is administered orally in tablet format These should be taken 30 minutes before going to sleep. Ideally they are taken with liquid (water). Doxylamine can also be taken in sachets (powder), pouring its contents onto the tongue.
On the other hand, regarding meals, it can be taken before or after them.
Indications
The use of doxylamine is indicated for people over 18 years of age The main indication for doxylamine is the short-term treatment of insomnia. Insomnia disorder involves difficulty falling asleep (onset insomnia) and/or maintaining it (maintenance insomnia).
Additionally, sometimes, people who have insomnia wake up early (terminal insomnia).
Other indications for doxylamine are: the treatment of the common cold (helps relieve symptoms such as: sneezing, runny nose and nasal congestion), as well as the treatment of cough. Doxylamine is usually taken in combination with decongestant products or drugs.
Insomnia disorder: what is it?
Since doxylamine is primarily indicated for the treatment of insomnia, Let’s see, broadly speaking, what this sleep disorder consists of, which can interfere so much in a person’s life
Insomnia disorder (primary insomnia), defined as such in the DSM-5 (Diagnostic Manual of Mental Disorders) involves difficulty initiating or maintaining sleep. In addition, it makes it difficult to have a restful sleep.
Symptoms last at least 1 month. On the other hand, the sleep disturbances that this disorder causes (or the associated daytime fatigue) lead to significant discomfort for the individual (or functional impairment).
According to the ICD-10 (International Classification of Diseases), the symptoms of primary insomnia have to appear at least 3 times a week (also for at least a month, the same as the DSM-5).
This disorder is more prevalent as age increases, and it is also more prevalent in women. Primary insomnia is the most prevalent sleep-related disorder worldwide (it is estimated that between 1 and 10% of the adult population suffers from it).
Precautions
Some considerations and precautions that should be known regarding doxylamine are: Doxylamine should not be administered to induce sleep in children; It should not be taken with alcoholic beverages or grapefruit juice either
As we mentioned at the beginning, its administration should be carried out from 18 years of age, never to minors. It should not be administered for more than 7 days (this is a short-term drug treatment).
Other aspects to know about doxylamine are that we should reduce its dose (or take it earlier) in the case of daytime sleepiness.
Some pathologies
Also We must be cautious with doxylamine in the case of epilepsy, heart failure, or being an elderly person present urinary obstruction or retention, etc.
We must know that this drug could worsen the symptoms of dehydration or heat stroke (this is due to the reduction in sweating generated by its anticholinergic effects).
Pregnancy and lactation
Doxylamine is contraindicated if you are pregnant. As for breastfeeding, it is not recommended, since doxylamine is very likely to be excreted in breast milk and the baby may be sensitive to the effects of antihistamines. Thus, there would be a risk for the baby.
Side effects
The side effects that doxylamine can cause are the following: headache, agitation, nausea, drowsiness, dry mouth, nose and throat nervousness and increased chest congestion.
On the other hand, there are two adverse effects of doxylamine that can be serious, and that is why it is necessary to call the emergency room if they occur; These are: vision problems and difficulties urinating.
Adverse reactions
On the other hand, the adverse reactions that doxylamine can cause are: dry mouth, drowsiness, constipation, urinary retention, vertigo, blurred vision and increased bronchial secretion.
