Adverse effects

Just as any other medication methadone may have adverse effects. They include:

•    Weakness, sleepiness;
•    Headache, temporary loss of consciousness (syncope);
•    Weight gain, fluid retention, anorexia;
•    Euphoria, hallucinations, insomnia, loss of orientation, decreased libido;
•    Heart rate disorders: bradycardia, palpitations, prolongation of the QT interval (heart rhythm disorder that can cause serious irregular heart rhythms that hinders the heart’s ability to pump enough blood for the body);
•    Flushing of the face, low blood pressure;
•    Pulmonary edema, suppressed breathing;
•    Nausea, vomiting, constipation;
•    Inflammation of the tongue, dry mouth;
•    Impaired function of the gall bladder ducts;
•    Rashes, itches, increased sweating;
•    Urine retention;
•    Decreased potency in men and lack of menstrual cycle in women;
•    Psychological dependence and physical addiction
•    Overdose – the risk is particularly high for people who have never used similar substances and especially children. Therefore, methadone should always be kept away from children in a tightly sealed and labeled container.