Overview of amitriptyline side effects
Amitriptyline [amee-TRIP-ti-leen] is a tricyclic antidepressant. There are various amitriptyline side effects seen in the treatment of depressed people.
Brand names or other names: Alin, AMWEL, AMIPRES, QMED (elite, DEPTYLINE, TRIAD, etc.
Amitriptyline Side effects
The following are amitriptyline side effects;
- Hypotension
- Tachycardia
- Palpitation
- Arrhythmias
- Heart block
- Stroke
- Changes in AV conduction & ECG
- Myocardial infarction
- Confusional state with hallucinations, disorientation, restlessness, insomnia, anxiety, excitement, nightmares, disturbed concentration, numbness, tingling, and paresthesia
- Ataxia, incoordination, and tremors
- Dysarthria, peripheral neuropathy, and extrapyramidal symptoms (for example, tardive dyskinesia)
- Seizures
- Dry mouth and tinnitus
- Blurred vision
- Increased intraocular pressure
- Mydriasis
- Hyperpyrexia
- Paralytic ileus
- Urinary retention
- Urinary tract dilation.
- Skin rashes, urticaria, & photosensitization
- Edema mainly in the face and tongue
- Bone marrow depression including eosinophilia, agranulocytosis, thrombocytopenia, and leukopenia
- Blood dyscrasias
- Nausea, vomiting, diarrhea, epigastric distress, anorexia, peculiar taste, stomatitis
- Increased frequency of urination
- Escalate perspiration
- Drowsiness
- Parotid swelling
- Dizziness
- Weakness
- Fatigue
- Headache
- Alopecia
- Gynaecomastia (abnormal enlargement of non-cancerous breast in males)
- Enlargement of the breast
- Impotence
- Galactorrhoea
- Libido decreased or increased.
- Swelling of testicular
- Elevation or lessening of the blood sugar levels.
- Inappropriate (unsuitability) antidiuretic hormone(ADH) secretion syndrome
- Gain or loss of weight
- Rarely seen amitriptyline side effects are: hepatitis, including altered liver function and jaundice, Coma, or death.
If various amitriptyline side effects present after use, consult your doctor or pharmacist.
Amitriptyline Indications (Uses)
- Depression (Mild to severe)
- Unlabeled uses of amitriptyline medications are listed below;
- Anxiety conditions
- Insomnia (sleep disorder)
- Treatment-resistant depressed patients
- Chronic pain syndromes include
- Fibromyalgia (musculoskeletal or muscular pain with localized tenderness and stiffness)
- Neuropathic pain/ chronic pain conditions, migraine headache in the patients, low back pain in a patient’s body.
Dosage (oral) in depression:
In adults:
- Initially, range between (50-75) mg/day as a single dose taken at bedtime or in divided doses;
- It may be increased up to 150 mg per day or ranged from 50 to 100 mg at bedtime
- It may be increased by dose range from 25-50 mg up to 150 mg in hospitalized patients,
- It may be initiated with a dose of 100 mg/day; the total daily dose may be increased up to 300 mg is the maximum dose of amitriptyline.
In geriatric (old age) patients or adolescents:
- Dose 10 mg TID (3 times a day) and dose 20 mg at bedtime, or dose 25 mg at bedtime
- Initially, slowly or steadily increased to 100 mg/day as a single dose or divided dose at bedtime
Mechanism of action (amitriptyline side effects)
- It inhibits the norepinephrine transporter (NET)
- Leads to blocking the reuptake of noradrenaline (NA) into the neuron.
- It enhances the availability of noradrenaline/norepinephrine at the receptors in the central nervous system (CNS).
TCAs (Amitriptyline) inhibit the serotonin transporter (SERT), which leads to blocking the reuptake of 5-HT into neurons & enhance the availability of serotonin (5-HT) at the receptors in the central nervous system (CNS).
TCAs (Amitriptyline) blockade muscarinic (atropine-like actions), alpha-1 adrenergic, and H1 receptors.
Pharmacokinetics
- Absorption: Orally taken, this medication is well absorbed from the Gastrointestinal tract.
- Distribution: Distributed widely throughout the body
- Plasma protein binding (PPB) capacity is about 95%
- Metabolism/ excretion:
- Extensively metabolized in the liver because of the cytochrome P450 2D6 enzyme.
- Few metabolites have antidepressant actions.
- It goes through enterohepatic recirculation & is secreted into gastric juices in the body.
- Probably, it crosses the placenta in the mother & enters breast milk.
- Plasma half-life: 10-50 hours.
Contraindications of amitriptyline
This medication (amitriptyline) is not used in patients who have already developed clinical abnormalities because this medication increases the severity of the present clinical abnormalities in the patients.
- Glaucoma (angle-closure glaucoma)
- Epilepsy
- Ischaemic heart disease
- Arrhythmia
- Mania
- Enlarged prostate
- Known history of QTc prolongation
- Recent MI
- Concomitant use with Monoamine oxidase inhibitors (MAOIs) or within 14 days of discontinuing MAOIs; linezolid, IV methylene blue, etc.
Used cautiously in:
- The risk may be greater in adolescents or children.
- Patients with cardiovascular disease.
- Prostatic hyperplasia (due to increased risk of retention of the urine)
- Chronic constipation
- History of seizures
- Renal and hepatic impairment
- Obesity: It uses if needed & maternal benefits outweigh the risk to the fetus
- Lactation: It may cause sedation in infants
- Pediatrics: Safety not established in children under 12 years
- Geriatrics: Geriatric (elderly) patients are at increased risk of side effects secondary to sedative effects & anticholinergic side effects.
Drugs interactions
- The risk of serotonin syndrome increases with SSRIs, TCAs, Lithium, fentanyl, Triptans, and tramadol.
- May lessen plasma levels with barbiturates, other convulsants, & rifampicin
- May increase plasma levels with methylphenidate, cimetidine, calcium channel blockers, and antipsychotic drugs
- May precipitate cardiac arrhythmias with the hormone of the thyroid gland.
- May lessen the antihypertensive effects of debrisoquine, clonidine, and guanethidine.
- May increase pressor effects of epinephrine & norepinephrine (NE)
- May increase ventricular arrhythmias with
- Antiarrhythmic drugs such as amiodarone, quinidine
- Antihistamines drugs
- Terfenadine
- Some antipsychotic drugs (pimozide, thioridazine, & sertindole)
- Sotalol, cisapride, & halofantrine.
- The risk of serotonin syndrome increased with MAOIs, methylene blue, and linezolid.
