What should you know about medicines that cause rhabdomyolysis?

Rhabdomyolysis is muscle breakdown that releases muscle contents into the bloodstream. Risk can change with the medicine itself, a higher dose, interactions with another medicine, dehydration, infection, or strenuous exertion. Possible signs include muscle soreness, weakness, swelling, unusual fatigue, and dark or tea-coloured urine. Muscle soreness after exercise is common for other reasons too, so a symptom alone cannot identify the cause. Blood and urine tests help clinicians check muscle injury and kidney effects.

Call the prescriber or an urgent medical service when new muscle pain or weakness follows a medicine change. Prepare the names, strengths, timing, and last doses of all medicines, supplements, and recreational substances. Do not double a missed dose or make an unsupervised change to ongoing treatment. Pause strenuous exercise until assessed. A clinician may advise monitoring, fluid treatment, a change in medicine, or further tests depending on the findings.

Go to urgent care for dark urine, very little urine, severe weakness, rapidly increasing muscle pain or swelling, vomiting, confusion, fainting, or inability to move normally. Breathing trouble, chest discomfort, or collapse requires emergency help. Take medicine packaging or a current list, including recent antibiotics, supplements, and dose changes.

Ask whether an interaction or dose issue may be involved, which tests are needed, and whether you should pause or replace a medicine. Ask when activity can resume, how kidney function will be followed, and which future symptoms should trigger immediate help.