A positive tensilon test in a dog with myasthenia gravis The Tensilon test is used to diagnose myasthenia gravis. Patients positive for the disease should show an improvement in muscular strength following administration of Tensilon - edrophonium - IV. Edrophonium is a very short acting anticholinesterase and therefore increases the effective amount of acetylcholine at the neuromuscular junction in patients with myasthenia gravis. | Pharmacy Era