Pharmacist provides overview of common drug interactions

On July 6, the Fallbrook Regional Health District’s Woman of Wellness program was on "Drug interactions and

Over-the-Counter Implications". The guest speaker was Don Weeks, a pharmacist at CVS.

Weeks explained that even though over the counter (OTC) medications can be bought without a prescription, they are regulated. However, even though people assume they are safe, and they are wonderful products (since you don't have to go to the doctor to get them), they can be misused.

He also said, individual medications may not be appropriate for everyone, so consulting a pharmacist when looking for an OTC medication is a good idea.

To find the right information, it also helps to read the labels carefully. For instance, he said, on any decongestant there is a big warning: "Don't take if you have heart disease" as they can raise a person's blood pressure.

If you ask for help at the pharmacy, Weeks recommended "make sure the person who is helping you has all the information (i.e. if you are suffering from a fever as well as a cough) – be specific with what your questions are" including what kind of a cough as different coughs have different remedies.

According to Weeks, the OTC market is $14 billion a year, 60 percent of drug sales. They are convenient; there are lots of products and it's a big business, he said.

There may be 100 single ingredients that when combined make 300,000 products. He continued, consumers will find that there can be exactly the same ingredients in two products. Sometimes, the only difference between two products, even two made by the same company, is that they have different names. “You need to read labels,” he said, when looking for an OTC medication.

People should also be aware that the amount of ingredients listed on labels may be per teaspoon or per tablet, not per dose.

When it comes to drug interactions, it is important to know how drugs affect people with certain diseases or other conditions. For instance, people with high blood pressure can take over the counter medications for four or five days without harm. “Being sick itself can raise one’s blood pressure,” Weeks said.

He had a few warnings about the use of decongestants. For one, he said decongestants can be used to make meth. He also explained that the problem for most people is that nasal sprays shrink tissue so they can breathe through their noses, but as the tissue shrinks, it puts pressure on the nasal passages. Three to five days of using a decongestant causes the body to send more blood to the blood vessels in the nose, creating rebound congestion.

The more often a decongestant is used in a day, the more likely a rebound will happen, so they are not meant for round-the-clock use, Week’s said. He added that the long lasting decongestants are better as the rebound effect is almost non-existent when using the medication just once a day. He recommended using them at bedtime to get a good night’s sleep which also helps with recovery.

When asked about pain control, there are good options in OTC pain medication, Weeks said. A non-steroidal anti-inflammatory, aspirin is used for thinning blood but, otherwise, there has been a change is how aspirin is used now. “Aspirin is an excellent anti-inflammatory but hard on the stomach,” he said.

If someone asks a pharmacist for advice about pain killers, it is important to describe the pain as chronic or temporary (if it is caused by a fall or pulled muscle for example).

For a chronic pain like arthritis which is not going to go away, Weeks recommended an anti-inflammatory that “doesn’t tear apart your stomach, one that doesn’t require three or four doses.” He suggested taking a pain killer twice a day, morning and evening, as it is better to take it with a meal.

For an injury, pain that will go away, Weeks advised doses of pain killer every four to six hours for three to four days.

Acid reducers are another widely used medication. He said proton pump inhibitors are not antacids; they don’t do anything to existing heart burn. What H2 blockers do is tell the body not to produce any more acid, Weeks explained. Instead, use liquid antacid or Tums he said as they are "safe and do more good than harm."

Taking two different kinds of pills at the same time isn't good; they either won't work or will work like a stronger dosage he said, adding that calcium is one that will interfere with medications and should be taken separately.

Another kind of interaction happens when medications go through a person's liver, Weeks said. Since the liver can filter out 70 percent of some drugs, medications that are put under the tongue work better as they are absorbed directly into the bloodstream.

Weeks also answered questions about expiration dates on medications. They are the manufacturer's guarantee that the medication is 98 percent effective on that date, but that doesn't mean it won't last for 15 years, he said.

Some medications do not go bad, however, aspirin is an organic acid that decomposes into acetic acid. If anyone is not sure their aspirin is still good, he recommended they take a whiff of it; if it smells like vinegar, it is not good. "It won't hurt but won't help either," he said.

When asked about pain relieving creams, he warned that Aspercreme has an aspirin derivative in it. Tiger Balm and Blue Emu have menthol and camphor in them, which increases blood flow. Weeks recommended capsaicin cream which "really has good pharmacology". Lidocaine is not meant to be used over and over again, he added; on 12 hours, then off 12 hours is important to remember when using it.

Anyone who is on a prescription should check with a pharmacist before using OTC medications was his final piece of advice.