How many Unisom can I take without it killing me?

Well, that's a very vague question, and kind of hard to answer. Is your problem really terrible insomnia? If so, you might want to address the nature of the insomnia, rather than overdosing on antihistamines, which is all that over the counter sleep remedies are.

You can take one or maybe two tablets of Unisom safely, but I'm really reaching--I'm guessing you have done this and it hasn't worked.

Anitihistamines have always had the often unpleasant side effects of making people drowsy. And for some, insomnia is just a rare tossing and turning night of being unable to doze off. For them, something that makes them a little drowsy is just fine. They are still, eyelids droopy and they are able to drift off.

For others, insomnia is a complicated, hard to pin down disorder that plagues them night after night for months, and even years. If this is your case, then trying to guess how many antihistamines is not going to help you in the long term. It might not even help you in the short term. True insomnia doesn't respond well to much, except addressing sleep-hygiene issues, depression or anxiety issues, and any physical problems that might keep you from getting a good nights' sleep.

There are some good prescription sleep medications available, but I'd recommend researching sleep-hygiene first. Once you start on the road of sleep meds, it's really hard to fix sleep hygiene and revert off the meds.

Sleep hygiene is a concept that we all know but sometimes forget: keep your lights off, room cool. Use your bed only for sex and sleep. Don't fall asleep with the TV on. Do relaxation techniques before bed, and avoid aerobic exercise 2 hours before bed. Keep a regular bedtime, and learn to rest your brain before bed. Don't work in bed. Keep a regular bedtime routine, and consistent morning time. Don't nap--even though research may show that nap times may be good for us, some times naps disrupt our sleep patterns.

Have a comfortable bed, with good sheets. Use sleep masks, ear plugs and a good pillow.

All these things just scratch the surface, and you may need a sleep doctor to do a study to see if you have a disorder such as apnea or other condition. But, for sure, antihistamines are only beneficial a scant number of times.