Not Medical Advice: Pill imprint M 51 has been identified as Amitriptyline hydrochloride 25 mg.
Amitriptyline is used to treat symptoms of depression and is in a class of medications called tricyclic antidepressants. It functions by increasing the amounts of certain natural substances in the brain that are needed to maintain mental balance.
Amitriptyline is also used to cure eating disorders, post-herpetic neuralgia (the burning, stabbing pains, or aches that might last for months or years after a shingles infection), and to prevent migraine headaches.
Amitriptyline may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
Nausea; vomiting; drowsiness; weakness or tiredness; nightmares; headaches; dry mouth; constipation; difficulty urinating; blurred vision; pain, burning, or tingling in the hands or feet; changes in sex drive or ability; excessive sweating; changes in appetite or weight; confusion; unsteadiness.
To view other Amitriptyline side effects visit Nlm.nih.gov.