Provocholine, or methacholine, is in the drug class of miscellaneous uncategorized agents. This means that Provocholine is used to carefully diagnose asthma in patients. This is done by either an intravenous solution or the patient may be hooked up to a nebulizer. A nebulizer is a device in which the medicated solution is turned into a vapor and inhaled. This is normally not an effective method of delivering medication unless the treatment is needed in the lungs specifically. Provocholine, for the safety of the patient, must not be administered anywhere other than a hospital or clinic with services that can handle an asthma attack, should one occur.