I have terrible allergies and my doctor gave me a prescription of cyproheptadine. Is this a good medication?

If ever a medicine sucked for allergies, then it has to be cyproheptadine. If you doctor gave you a script of this medication, it means you are getting second-rate medical care from a buffoon. Cyproheptadine is one of the oldest drugs in medicine and is almost never prescribed today. 

The drug is classified as an anti-histamine and it is unlikely that any doctor trained in the modern era of medicine would ever prescribe it, unless he owns the pharmaceutical company. The drug has many side effects and it is most likely that that the pharmacy is trying to get rid of its supplies from the 1950s. 

If you have allergies, you first need to change your doctor and then seek an allergy specialist.  Ask for a second generation anti histamine. 

I am allergic to latex. Are there any non latex condoms available?

Sure, there is a big industry making everything non-latex these days and condoms are a big part of the business. For decades no one complained about latex condoms but in the last decade many reports about allergy to latex have cropped up. Non-latex condoms are available for those who have allergy and are just a wee bit more expensive. The studies so far have shown that that non-latex condoms do not work as well as the latex condoms in preventing pregnancy. The non-latex condoms are also more prone to breakdowns from small perforations. However, most consumers prefer the non-latex variety because they feel natural and have a certain eroticism.