Dr P Ravi Shankar

Pokhara

I was talking with my mentor and guide, Dr Aravindam Theodore the other day. Theodore sir has a keen interest in how society responds to illness. The ‘first response’ pattern of a society towards illness has also fascinated me. Self-medication due to various reasons is a common response to ill health. The other day I was reading an article in The Himalayan Times about how doctors were of the opinion that self-medication was injuring health. However, due to various reasons self-medication will always be present in human society. We can only educate people and restrict the number of drugs that can be sold over the counter. Today we will look at a few drugs, which are commonly used for self-medication, and a few basic precautions to be followed while using drugs on your own.

What is self-medication?

It is the use of medicines by a person on his/ her own without consulting a medical practitioner. What are the common illnesses where you will try self-treatment before going to a doctor? The common problems are upper respiratory tract infections, joint pains and aches, vomiting, cough, general weakness and heart burn. The drugs commonly used to treat these illnesses are nasal decongestants, antihistamines, Paracetamol and other NSAIDs, iron tablets and tonics, anti-vomiting drugs, antacids and cough syrups. A drug is a molecular sword and we should be very careful while using them.

Many of us suffer from the so called ‘diseases of civilisation’ like diabetes mellitus and hypertension. Drugs used for self-medication may interfere with the control of blood pressure in a hypertensive patient or control of blood sugar in a diabetic. Also kidney and liver function may decline with age or disease and a drug used for self-medication may have a disastrous effect. Our genetic make-up maybe a reason why some of us cannot tolerate certain drugs.

Let us review some common drugs used for self-medication with nasal decongestants. Suppose you are struck down by the common cold. The lining of your nose swells up, fluid starts dribbling from your nose and breathing becomes a chore. Your nasal lining is congested. A ‘decongestant’ is a drug which relieves the congestion. How does it work? During a common cold (and certain other conditions) there is dilatation of the blood vessels in the nasal mucosa. The blood vessels also become more leaky causing seepage of fluid into the surrounding tissues.

Many substances have been implicated, but the main culprit is a substance which you may have studied in high school biology — Histamine. A nasal decongestant (common brands are otrivin and nasivion) constricts or narrows the blood vessels. The blood flow is decreased and the vessels become less leaky. Something like shutting off or decreasing the water supply to a leaky pipe. Many of you must have used these nose drops at least once.

But if you are suffering from high blood pressure then you should be very careful while using these drugs. They increase the blood pressure and your ‘BP drugs’ may no longer be effective.

Using these drugs for a time period greater than one week may interfere with the blood supply and nutrition of the nose and lead to a condition called ‘atrophic rhinitis’. So never use them for a time period greater than a week.

Since histamine is a key player in causing a

dripping nose and allergy, a drug called an ‘antihistamine’ may be effective. Histamine acts on two

main types of receptors, H1 and H2. H1 is mainly

responsible for allergy while H2 is present in the

lining of the stomach and is involved in the production of acid.

The drugs which prevent the action of histamine on the H1 receptor are diphenhydramine (benadryl), pheniramine (avil), terfenadine (trexyl) and cetrizine (alerid). There are many more drugs and I have selected only a few representatives. Drowsiness is a common problem with these drugs though it is less with the last two. If you are taking these drugs then do not drive or operate machinery. Alcohol should be avoided as well. Terfenadine can produce irregular beating of the heart (arrhythmias). The drug is mainly metabolised by an enzyme CYP3A4. Erythromycin and clarithromycin (two commonly used antibiotics) inhibit this enzyme. There is a rise in terfenadine levels. A dangerous arrhythmia, torsades de pointes (so called because of a fancied resemblance to the steps of a ballet dancer) results. Many countries have banned terfenadine because of this problem.

Iron is an element which has symbolised strength and vitality since time immemorial. Iron tablets and tonics containing iron are commonly used for weakness. Tetracycline is an antibiotic used for a variety of conditions including acne. Tetracyclines form a complex with iron and interfere with iron absorption. Iron should be taken after food as otherwise, it may cause severe irritation of the gastrointestinal tract. However, food interferes with iron absorption and we have to use a higher dose. Antacids (drugs used to treat heartburn and peptic ulcer) may interfere with iron absorption.

Ciprofloxacin is a commonly used antibiotic. Iron may interfere with the absorption of ciprofloxacin and reduce the effect of the antibiotic. Giving a two to three hour gap between the two drugs may be a method of decreasing the drug interactions.

Diarrhoea is a common disease in our part of the world. Frequent passage of stools may interfere with matters of business and pleasure. Just imagine undertaking a long bus journey in this condition. Diphenoxylate and atropine combination (lomotil) and loperamide (Imodium) are commonly used. But in cases of infective diarrhoea (where a bug has lodged and multiplied in your gut) these drugs can be disastrous. The body relies on propulsive movements of the gut among other things to flush out the bug from the system. Using a drug which decreases intestinal movement will lead to stasis and multiplication of the invading bug. Most cases of diarrhoea are self-limiting and oral rehydration solution (ORS) to replenish the salts lost from the body is all that is required.

So be careful when you use a drug on your own. You can look at the package insert (paper inserted into the drug pack which details the composition, adverse effects, uses, contraindications, etc, of the drug) and try to get some information. Always tell your doctor about any drugs you may be using. Failure to do so may lead to an interaction with the prescribed drug. You go with one disease and end up with another!

As succinctly put by Napoleon Bonaparte in 1820, “I do not want two diseases — one nature-made, one doctor-made.” A little caution will go a long way!