Paracetamol is the first-line treatment for pain relief in patients with osteoarthritis. Non-steroidal anti-inflammatory drugs (NSAIDs) can be used but tend to cause gastrointestinal side effects. The roles of COX-2 inhibition and drugs aimed at preventing cartilage destruction require evidence from long-term trials. Rheumatoid arthritis may be treated with NSAIDs and glucocorticosteroids. In the early stages of the condition, disease modifying antirheumatic drugs (DMARDs) are recommended. The pain of gout can be treated with non-salicylate NSAIDs; alternatives are colchicines and allopurinol. Muscle spasm and spasticity can be treated with GABAB receptor agonists, such as baclofen, or GABAA potentiating drugs, such as the benzodiazepines. Peripherally acting drugs such as dantrolene lack central nervous system side effects. Drugs inhibiting the enzyme acetylcholinesterase are used to treat the autoimmune disease myasthenia gravis, in which the body produces antibodies to nicotinic receptors for acetylcholine.