User:MattKingston/Scratch bethanechol

Carbachol (Kar-ba-kol [key]), also known as carbamylcholine, is classified as a cholinergic. It is primarily used in the treatment of glaucoma, but is also used during ophthalmic surgery. In most countries it is only available by prescription.

Indications
Carbachol eyedrops are used to decrease the pressure in the eye for people with glaucoma. It is sometimes used to constrict the pupils during cataract surgery.

How to take

 * To prevent infection, always wash your hands before and after administering any eye drops. Do not let the applicator touch any surface, including the eye.
 * Tilt your head back and slightly to the side that you're administering the drops.
 * Pull the lower eyelid away from the eye to make a pocket for the drops.
 * Put 1-2 drops in the eye as prescribed.
 * Gently close the eye without blinking and keep they eye closed for 1 to 2 minutes with your finger pressed on the inside corner of the eye.
 * Repeat for the other eye if prescribed.

If you miss a dose
If you remember soon after your scheduled dose, apply the drops as prescribed. If your next scheduled dose is soon then skip the missed dose and take the next dose on schedule, do not double the dose. If you miss more than one dose, contact your health care professional for advice.

How to store

 * Keep out of reach of children.
 * Store in a dark place.
 * Store at room temperature.
 * When your prescription expires, return the unused medication to the pharmacy for proper disposal.

Cautions

 * Precautions
 * Pregnancy
 * Breast feeding
 * Geriatric
 * Pediatric
 * Interactions

Chemistry and pharmicokinetics
Carbachol is a choline ester and a positively charged quaternary ammonium compound. It is not well absorbed in the gastro-intestinal tract and does not cross the blood-brain barrier. It is usally administered topical occular or through intraoccular injection. Carbachol is not easily metabolized by cholinesterase, its duration of action is 4 to 8 hours with topical administration and 24 hours for intraoccular administration. Since carbachol is poorly absorbed through topical administration, benzalkonium chloride is mixed in to promote absorption.

Mechanisms of action
Carbachol is a parasympathomimetic that stimulates both muscarinic and nicotinic receptors. In topical occular and intraoccular administration its principal effects are miosis and increased aqueous humour outflow.

Indications
Topical occular administration is used to decrease intraoccular pressure in people with primary open-angle glaucoma. Intraoccular administration is used to produce miosis after lense implantation during cataract surgery.