Possible Drug Interactions of OTC Drugs and Preventive Measure
Over-the-counter (OTC) products are medicines you can buy without a doctor’s prescription.In the United States, consumers legally have access to drugs by two mechanisms: access with a prescription provided by a licensed health care professional or access without a prescription, by over-the-counter purchase. Many other countries have a similar classification of drugs. In addition, some countries have a third mechanism, by which certain sales without a prescription require consultation with a pharmacist or in which the marketing of certain drugs is limited to venues where such consultation is available.
States that FDCs should in guidance on the Investigation of Bioavailability general be assessed as to the bioavailability and & Bioequivalence. Bioequivalence of the individual active ingredients either separately (in the case of a new combination) or as an existing combination. Studies should be designed to detect any pharmacokinetic drug-drug interaction.
Drug abuse is the nontherapeutic use of any psychoactive substance, including alcohol, in such a manner as to adversely affect some aspects of the user's life. The substance may be obtained from any number of sources: by prescription, from a friend, over-the-counter, or through the illicit market. The use pattern may be occasional or habitual.
If you use 2 or more drugs at the same time, the way your body processes each drug can change. When this happens, the risk of side effects from each drug increases and each drug may not work the way it should. This is called a "drug-drug interaction." Vitamins and herbal supplements can affect the way your body processes drugs too.
A drug interaction is a change in the effect of a drug caused by some other substance. In some cases, there is a change in the helpful effects of a drug and in other cases there is a change in side effects. It is important to remember that alcohol and tobacco, as well as prescription and nonprescription medicines, can be involved in drug interactions. Vitamins, natural remedies, and certain foods may also interact with drugs.
Many over-the-counter sleeping medications use antihistamines, which cause drowsiness. Diphenhydramine is the most common antihistamine used non-prescription sleep aids. Some drugs contain diphenhydramine alone (Nytol, Sleep-Eez, Sominex) while others contain combinations of diphenhydramine with pain relievers (Anacin P.M., Excedrin P.M., Tylenol P.M.). Doxylamine (Unison) is another antihistamine used in sleep medications. Certain antihistamines indicated only for allergies, such as chlorpheniramine (Chlor-Trimeton), diphenhydramine (Benadryl), or hydroxyzine (Atarax or Vistaril) may also be used as mild sleep-inducers.
Some nutrients can affect the way you metabolize certain drugs by binding with drug ingredients, thus reducing their absorption or speeding their elimination. For example, the acidity of fruit juice may decrease the effectiveness of antibiotics such as penicillin. Dairy products may blunt the infection-fighting effects of tetracycline. Anti-depressants called MAO inhibitors are dangerous when mixed with foods or drinks that contain tyramine (beer, red wine, and some cheeses).
Nonprescription, or over-the-counter (OTC), drugs have a prominent place in the medicine cabinets of most elderly people. Analgesics (painkillers), antacids, cough and cold preparations, and laxatives are among the OTC drug products most frequently used by older people. While many people don't think of these as drugs, OTC drug products can be the cause of adverse side effects in older patients. Aspirin, for instance, can increase the effect of blood thinners, and decrease sodium and chloride excretion--a matter of concern to those with congestive heart failure.
Many OTC products are advertised to relieve heartburn or acid reflux. These include antacids, bismuth subsalicylate, H2 blockers, proton pump inhibitors and combination medicines. Combination medicines may include two or more of the following drugs.Don’t take these drugs if you have an allergy to any of the ingredients. Phenylalanine is an example of an ingredient in some antacids that can cause a problem for certain people. If you have a condition called phenylketonuria, you shouldn’t take a medicine that contains phenylalanine.Medications known to interact with antacids include:
- Antibiotics, such as tetracyclines or quinolones (Levaquin, Cipro)
- Antifungals, such as itraconazole (Sporanox)
- Digoxin (Lanoxin), a medication used to treat congestive heart failure
- Iron supplements
Don’t take bismuth subsalicylate if you’ve ever had an allergy to aspirin or any other product that contains salicylates. Also don’t give bismuth subsalicylate to children who may have the flu or chickenpox because they will have a higher risk of Reye’s Syndrome.
An example of the challenges involved in assessing the safety of an over-the-counter drug is provided by studies of the use of ibuprofen for short-term treatment of fever in children. The proposal to use ibuprofen in children aroused concern about the risks of Reye's syndrome, gastrointestinal bleeding, and renal failure. Renal failure was a particular concern in children who might be dehydrated because of an acute illness. These risks were evaluated in a community-based trial in which 84,192 children with fever were randomly assigned to receive acetaminophen or ibuprofen.
The trial identified no ibuprofen-associated cases of Reye's syndrome or renal failure, and there were no significant differences between the treatment groups in the rates of gastrointestinal bleeding. The results thus provided substantial reassurance that ibuprofen is safe for over-the-counter use in children.Because this drug is available over the counter, the responsibility for recognizing these conditions now rests with the consumer rather than the health care professional.
Other ingredient-related warnings concern your diet while you’re taking an antacid or acid reducer. For example, unless your doctor tells you it’s OK, don’t use products that contain sodium bicarbonate or aluminum hydroxide and magnesium carbonate if you’re on a low-salt diet. Don’t take magnesium hydroxide if you’re following a magnesium-restricted diet.
If you have kidney disease, you shouldn’t use products containing calcium carbonate or aluminum hydroxide and magnesium carbonate without your doctor’s recommendation.Drug-condition interactions may occur when an existing medical condition makes certain drugs potentially harmful. For example, if you have high blood pressure you could experience an unwanted reaction if you take a nasal decongestant.
Herbal products are not rigorously tested and thus cannot be marketed for the diagnosis, treatment, cure or prevention of disease.Ginkgo biloba has potential interactions with garlic, vitamin E and medications with antiplatelet or anticoagulant properties. Patients should be advised not to use ephedrine-containing supplements if they have cardiovascular disease, hyperthyroidism, diabetes mellitus, benign prostatic hypertrophy or glaucoma.
To reduce your risk of drug reactions, follow these guidelines from the American Academy of Family Physicians:
- Read labels carefully, and understand the ingredients in each drug and any possible side effects they can cause.
- Before taking a drug, ask your health care provider or pharmacist these questions:
- Can I take it with other drugs?
- Should I avoid certain foods, beverages, or other products?
- How will the drug work in my body?
- What are possible signs of a drug interaction I should know about?
- Don't mix pills or break capsules into any food or drink unless directed to do so.
- Don't take any medication with alcohol.
- Don't take medication at the same time as vitamins or mineral supplements.
- To reduce or prevent drug interactions with antacids, it is generally recommended that you take antacids at least one hour before or two hours after other medications.
- Make sure you know what ingredients the product contains and understand any warnings or possible adverse effects.If you don't understand something, ask your doctor or pharmacist about it.
- Don't stir medicine into your food or take capsules apart (unless your doctor tells you to). This may change the way the drug works.
- Are you taking an herbal product, herbal supplement or other "natural remedy?"
- If so, are you taking any prescription or nonprescription medications for the same purpose as the herbal product?
- Have you used this herbal product before?
- Are you allergic to any plant products?
- Are you pregnant or breast-feeding?
- Don't take vitamin pills at the same time you take medicine. Vitamins and minerals can cause problems if taken with some drugs.
- Don't mix medicine into hot drinks unless the label tells you to. The heat may keep the drug from working as it should.
- It is very important for you to inform your physician of over-the-counter medications, herbal medications and prescribed medications because of the potential drug to drug interaction or herbal to drug interaction .A drug interaction is a change in the effect of a drug caused by another substance, such as another drug, herbal remedies, food or alcohol.
- In addition to medications and herbal products, food and beverages – such as grapefruit juice – can also interfere with the effectiveness of medications.
- Consider your heart disease before taking any over-the-counter medications, vitamins, herbal preparations or prescription medications or before having any medical or surgical procedures. Discuss any potential cardiac side effects or drug interactions with your primary care physician, cardiologist or pharmacist.
- Food-drug interactions can happen with both prescription and over-the-counter medications, including antacids, vitamins and iron pills.
- Know how to take drugs safely and responsibly. Remember, the drug label will tell you:
- what the drug is used for how to take the drug how to reduce the risk of drug interactions and unwanted side effects
- Do not stir medicine into your food or take capsules apart (unless directed by your physician). This may change the way the drug works.
- Always check for drug-drug, drug-food and drug-disease interactions. Remember to take a "new" drug history periodically
- Occasionally — especially when you first use insulin — you may notice redness and some slight swelling at the injection site. This may result from impurities in the insulin or could stem from a small amount of alcohol getting into the underlying tissue. To avoid this, let the injection site thoroughly dry if you clean it with alcohol.If skin irritation lasts more than two to three weeks or causes discomfort, talk to your doctor or another member of your diabetes care team. To minimize pain from injections:
- Make sure the insulin is at room temperature.
- Relax your muscles in the area of the injection.
- Penetrate the skin quickly with the needle.
- Don't change the direction of the needle during the injections
Over-the-counter status offers some clear potential advantages over prescription status.Of course, there are a number of potential disadvantages as well, including risks related to self-treatment by patients — risks of misdiagnosis, delays in obtaining a correct diagnosis, adverse interactions with other medications, reduced opportunities to receive counseling about possible lifestyle therapies (such as exercise and diet), poorer compliance (by patients who view over-the-counter drugs as different from "real" medications), use by patients who are unlikely to benefit from the drug but will nevertheless be exposed to its risks, and patterns of taking medications inappropriately (e.g., "if one is good, two are better").