Shopping can be  a fun event, but standing in the pharmacy, puzzling out which heartburn medicine to buy as your spicy lunch burns a hole in your stomach? Not so much . . .
In a recent survey 66 percent of adults said that picking the right nonprescription drug is enough to make their heads spin. Mulling over the multiple choices--there are more than 100,000 OTC meds available--gets a lot easier when you check with the pharmacist instead of trying to remember the advertisement you saw. Here are top choices for treating those annoying ailments--from hay fever to headaches--that can ruin your day.

Cold Sores
The Drug: Aciclovir (Zovirax)
Got that telltale tingle that signals that a cold sore is about to sprout on your lip? Aciclovir  can bring it to a halt. It prevents the virus from multiplying, which stops the cold sore from erupting.
Dash to a drugstore the minute you feel a cold sore coming on. Once the sore develops, using Acciclovir isn't as effective, because the time for prevention has passed Runner up: Abreva . If the sore has developed use a zinc cream or orajel to reduce the discomfort.
See a doc if the sore hasn't healed after 10 days.

Constipation
The Drugs: Metamucil and Dulcolax
When it comes to making regular deposits, the magic word is fiber. Metamucil is druggists' remedy of choice because it contains psyllium, a natural plant fiber that softens and bulks up your stools. Metamucil is effective and safe to take every day.

Constipation continued...
The downside is that the medication can take time to work--usually 12 to 72 hours--which is why pharmacists also recommend bisacodyl (brand dulcolax), a stimulant laxative that does the trick in less than 12 hours. Bisacodyl stimulates the intestine muscles to propel food through your body's gastrointestinal tract. It is gentler then senna.
Generic: Psyllium for Metamucil and bisacodyl for Dulcolax
If you use Metamucil powder, drink it as soon as you mix it with water. Otherwise you'll end up with a thick, rubbery blob in your glass. A stimulant laxative like bisacodyl should not be used for more than a few days in a row. Use it longer than and your bowels may start to rely on the medication to do the job.

Diarrhea
The Drug: Imodium
When a case of the runs tethers you to the toilet, Imodium can help slow the flow. It reduces the frequency of bowel contractions, it also gives your stools more firmness. Bismuth subsalicylate, the active ingredient in Pepto-Bismol, isn't as strong, which means the drug doesn't slow things down as efficiently.
Generic: Loperamide HCl
Try to pinpoint the cause of your gastrointestinal distress before you pop a pill. In some cases, you may actually be better off just riding it out. If you've got a case of food poisoning, for example, taking an antidiarrheal drug will prevent toxins from being flushed from your body, prolonging the entire episode. See a doc if your diarrhea hasn't gone away after 48 hours or you develop a fever.

Hay Fever and Allergies
The drug: Claritin
Allergens trigger your immune system to release histamine (an inflammatory compound), which causes runny nose, itching, sneezing, and congestion. Claritin sets up a roadblock against that histamine release to prevent allergy symptoms from occurring. Plus, it does not cause drowsiness, a common side effect from older drugs lik Benadryl and benefit #2 it works all day instead of only 4-6 hours.
Generic: Loratadine
The drug works best if you take it before you're exposed to the allergy trigger. So swallow a Claritin 30 to 60 minutes before you head out to mow the lawn or groom the cat.
See a doc if your symptoms don't let up or they become more severe while you're taking the medication.

Heartburn
The drug: Pepcid AC
This one knocks out heartburn by slowing down the acid-­producing cells in your stomach. (Antacids like Tums or Mylanta merely neutralize stomach acid after your body has already made it. Plus, antacids work for only one to three hours, but Pepcid can give you relief for up to 24 hours.
Generic: Famotidine. Runner up Zantac or ranitidine
Fine print: When symptoms are triggered by only certain foods take it before a meal. If you take it after a meal, when your belly's already in full revolt, you'll have to wait an hour  before you start feeling better.
See a doc if your heartburn is accompanied by difficult or painful swallowing, vomiting, or bloody or black stools.

Hemorrhoids
The drug: Preparation H Ointment
Flare-ups can happen when you're constipated (all that pushing), and they're especially common during and after pregnancy (ditto). This old remedy contains a combination of three lubricants--mineral oil, petrolatum, and shark liver oil--to soften and protect the skin, plus a topical version of phenylephrine HCl, a vasoconstrictor that shrinks tissues and relieves itching.
Generic: Any hemorrhoid treatment that contains the same active ingredients
Fine print: Although the ointment works generaly the best an anaesthetic cream for pain reduction may be preferred by some.
See doc if bleeding occurs, or if the problem persists for more than a week or worsens.

Motion Sickness
The drug: Bonine
Why it's No. 1: Meclizine hydrochloride, the active ingredient, is just as effective at preventing motion sickness but is less likely to make you nod off than dimenhydrinate, the ingredient in the original form of Dramamine. This one will probably get you better thru your scuba lessons. The nausea occurs when the part of the brain that detects motion gets mixed signals, The same thing happens when you're reading a book while riding in a car. Your body feels motion but your eyes don't register the movement, which sets you up for what is called a sensory conflict. 
Generic: Meclizine
Fine print:The key word in this product name is "less," it may still make you feel a bit sleepy.
See a doc if you have severe, uncontrollable vomiting.

Poison Ivy or Oak
The drug: Cortaid
Why it's No. 1: Last off-the-grid adventure leave you with the itchies? Grab Cortaid, which will decrease the swelling and discomfort of poison ivy faster than anything else.
Generic: Hydrocortisone
Fine print: It's not a good idea to use hydrocortisone on large areas, because too much could be absorbed into your bloodstream, leading to side effects such as inflammation and peeling, itchy, or irritated skin.
See doc if itching remains severe despite use of the product, if symptoms persist for more than seven days, or if the rash covers a large area. You may need an oral steroid instead.

Red Itchy Eyes
The drug: Visine-A
Why it's No. 1: Unlike drops that simply treat the appearance of red eyes by constricting the blood vessels, Visine-A also contains an antihistamine to relieve itchiness caused by allergies.
Generic: Allergy eye drops containing the decongestant naphazoline and the antihistamine pheniramine
Fine print: Using an eye drop containing a decongestant for more than three days in a row can make your eyes redder than they were to start. A decongestant works by shrinking swollen vessels, which restricts the amount of blood in the area, if you use it too often, when it wears off, your body sends a flood of blood back, which causes a rebound effect--essentially magnifying the original problem.
See doc if your eyes feel gritty, your vision becomes blurred, or the condition worsens or persists for more than 72 hours.

Stuffy Nose
The drug: Afrin
Why it's No.: 1 You feel stuffy, not because your head is full of mucus but because your blood vessels are swollen. The active ingredient in Afrin (oxymethazoline) is a vasoconstrictor that's very effective at shrinking those vessels.
Generic: Oxymethazoline
Fine print: Do not use longer then appr. 5 days to prevent rebound and possible addiction. If Afrin spray does not work long enough, try long acting Sudafed, although it may keep you awake. The combination sudafed/claritin called clarinase may give you best results.
See a doc if your symptoms don't improve within a week or you're also running a fever.

Tension Headache
The drug: Tylenol
Why it's No. 1: Aspirin and ibuprofen can also kill a headache, but they can irritate the stomach, causing cramps and sometimes bleeding.  Compared with other headache relievers, Paracetamol has the fewest side effects and interactions with other drugs.
Generic: Acetaminophen, Paracetamol
Fine print: Knock back fewer than three cocktails a day if you're taking Tylenol. Combining large quantities of alcohol and acetaminophen can cause serious liver damage. Try it with a cup of coffee instead. Caffeine is known to be able strenghten the effect of paracetamol for headaches.
See a doc if your headache worsens or lasts for more than 10 days.

Yeast Infections
The drug: Canesten
Why it's No. 1: When you've got an itch you can't scratch in public, reach for a tube of Canesten, which kills the overgrowth of the fungus that causes a yeast infection. It is the only product that's available in six-day, three-day, and one-day formulations.
Generic: Clotrimazole
Fine print: While the one-day and three-day formulations can cut down on the number of nights you spend in misery, it can still take up to a week for the infection to disappear. The shorter formulas keep working even after the last dose, so you might not feel better until after you've emptied the package.
See a doc if your symptoms don't improve or they worsen after treatment.