Physicians should advise patients to stop use of all PDE5 inhibitors, including VIAGRA, and seek medical attention in the event of a sudden loss of vision in one or both eyes. Such an event may be a sign of non-arteritic anterior ischemic optic neuropathy (NAION), a cause of decreased vision including possible permanent loss of vision, that has been reported rarely post-marketing in temporal association with the use of all PDE5 inhibitors. It is not possible to determine whether these events are related directly to the use of PDE5 inhibitors or to other factors. Physicians should discuss with patients the increased risk of NAION in individuals who have already experienced NAION in one eye. Physicians should also discuss with patients the increased risk of NAION among the general population in patients with a “crowded” optic disc, although evidence is insufficient to support screening of prospective users of PDE5 inhibitor, including VIAGRA, for this uncommon condition [see WARNINGS AND PRECAUTIONS and ADVERSE REACTIONS ].
A scientific review of a large number of trials and studies all involving melatonin and jet lag finds that melatonin is “remarkably effective in preventing or reducing jet-lag, and occasional short-term use appears to be safe.” The researches found that in nine out of 10 trials, when melatonin was taken close to the target bedtime at the destination (10 . to 12 .) there was a decrease in jet lag from crossing five or more time zones. The researchers also observed that daily doses of melatonin between and five milligrams worked similarly well, but subjects did fall asleep faster and sleep better after taking five milligrams compared to milligrams.