Latanoprost, sold under the brand name Xalatan among others, is a medication used to treat increased pressure inside the eye. This includes ocular hypertension and open angle glaucoma. It is applied as eye drops to the eyes. Onset of effects is usually within four hours, and they last for up to a day. Common side effects include blurry vision, redness of the eye, itchiness, and darkening of the iris. Latanoprost is in the prostaglandin analogue family of medications. It works by increasing the outflow of aqueous fluid from the eyes through the uveoscleral tract.