Prescription dangers How safe are the drugs you are taking?

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Prescription dangers

How safe are the drugs you are taking?

By Benson Kimathi

Consider this scenario: You are given some medication by your general

practitioner (GP) and after you get home, you decide to down the drugs with

a glass of nutritious grapefruit juice. The next thing you know, you are

seriously ill or hospitalised. This is one of many possible scenarios facing

patients who are on medication.

Do you take time to read the information leaflets that come with your drugs

to find out as much as possible about what you are swallowing? Do you bother

to ask why your pharmacist insists that certain drugs must be taken with

plenty of water, or after food? Do you question your doctor on everything

you do not understand? If the answer to any of these questions is no, then

you may have reason to worry.

Medicinal drugs are toxic substances that have been packaged in dosages that

cure the user safely. " The principle behind giving a treatment is that the

benefit outweighs the side-effects, " says Dr Nyikal, Chairman of the

Kenya Medical Association, and also a paediatrician with the Hurlingham

Children's Clinic, Nairobi.

Think, for instance, of a person who receives a transplanted organ (like a

kidney) to save his life, but whose system rejects the donor organ. " The

individual may have to be put on (cortico-) steroids for life, " explains Dr

Nyikal. That is in spite of the drug's scary side effects like diabetes and

osteoporosis (brittle bones).

Understanding your drugs can save you from joining the thousands who go to

hospital each year suffering from drug-related illnesses.

 Under-dosing and overdosing

Experts agree that most problems of under-dosing and overdosing occur

through self-medication, although doctors and pharmacists take their share

of the blame. As Dr Kamamia wa Murichu, chairman Pharmaceutical Society of

Kenya explains, the dosage for certain drugs is weight or age-dependent.

Through mistake or recklessness, a doctor may prescribe drugs to a patient

in dosages that do not match the age or weight. Research conducted in the US

shows that over three-quarters of adverse drug reactions are related to

dosage. People of low weight are more sensitive than their heavier

counterparts.

Before or after food?

Drugs like aspirin, which can harm the stomach, should be taken after food.

Likewise, those medications that must be absorbed quickly should be taken

before food. Consult your GP for guidance. Dr Murichu says that if insulin

is administered before food, or in excessive dosages, diabetic patients

suffer hypoglycaemic shock(due to too much sugar in the blood).

Drug interactions

According to the book 'Drug Interactions' by Ivan Stockley (The

Pharmaceutical Press, 1996), " an interaction is said to occur when the

effects of one drug are changed by the presence of another drug, food, drink

or by some environmental chemical agent. " If tetracycline is given with an

antacid, for instance, the two may form a complex compound that cannot be

absorbed.

Metronidazone (e.g. Flagyl), an important drug used to treat diseases like

vaginal trichomoniasis and amoebiasis, must not be taken with alcohol. Cases

of flushing and fullness of the face, breathlessness, tachycardia

(abnormally rapid heartbeat), giddiness, low blood pressure, nausea and

vomiting have been reported. Oral anti-coagulants (drugs that dissolve blood

clots) can prolong the time it takes for the blood to clot normally.

Taking certain drugs at the same time may also lead to drug absorption

interactions, where one drug interferes with the way the other is absorbed.

A few years ago, an alert was issued regarding the undesirable interaction

between astemizole (an antihistamine) and ketoconazole (an antifungal).

Until then both drugs had commonly been prescribed jointly.

What about harmless substances like grapefruit juice? Studies show that

grapefruit juice blocks a special enzyme in the intestines, making the body

unable to break down and absorb many medications. This way, ingested drugs

can accumulate to toxic levels, damaging or hindering the normal functions

of certain vital organs. Drugs reported to interact with the juice include

sildenafil citrate (Viagra), certain antihistamines, psychiatric medications

and some cholesterol lowering drugs.

Deciding what adverse drug reaction is genuine is, however, best left to the

experts. You may, for instance, blame your loss of libido on the

antidepressant you took the previous night. But how sure are you that your

depression is not the cause?

The ideal

Can we then ever have a situation where patients will be free of all

drug-related dangers? In modern world, maybe not. Dr Murichu explains that,

before a drug is released to the market, enough clinical trials have to be

done with a limited sample of the population to determine short-term side

effects. The long-term effects can only be discovered after the drug has

been in the market for some time. If pharmacists were to wait until all

possible data had been gathered, no new drug would ever enter the market.

What then should you do to be safe? For starters, do your homework. You

must, for instance, ask your GP questions on any unclear issues. Look

elsewhere if your doctor doesn't listen to your worries. Dr Nyikal holds

that doctors are ethically obliged to disclose to their patients the side

effects of drugs they prescribe. Additionally, find out as much as possible

about the drugs you take. Reading the information leaflets that come with

your medication can alert you of possible drug interactions or side effects.

Tell your doctor about other drugs you may be taking, and ask about those

apparently harmless substances that you will take concurrently. Alert your

practitioner on allergies or sensitivities you may have. It also helps to

master the names (brand and generic names) and physical characteristics of

drugs you take regularly. If you are given alternatives, ask why and how the

drug differs from the ones you have been taking.

Patients should desist from self-medication. Today Kenyans can walk into

drug stores and buy any drug over the counter. " Every time a patient gets a

fever, he thinks it is malaria, " says Dr Okello Agina, a Consultant

Obstetrician and Gynaecologist. " It is because Kenyans (have) abused

chloroquin that the drug no longer works. "

Dr Agina laments that " Pharmacists are playing judge, jury and executioner

when they diagnose, prescribe and dispense. This is both unethical and

illegal. " According to the British National Formulary of 1999, pharmacists

need to liaise with the prescribing doctor once they detect anomalies of

dosage or possible drug interaction in a patient's prescription slip.

Finally, always follow your doctor's instructions. Complete the dosage if

your doctor advises so, even if you feel better. You will also be doing

yourself and society much good if you report any strange reactions to

prescribed drugs.

The usual suspects

Common drugs that account for many of the medication accidents and errors

treated by doctors

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Dr. Kamamia wa Murichu, the chairman of the Pharmaceutical Society of Kenya

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Dr Kamamia wa Murichu, Chairman of the Pharmaceutical Society of Kenya,

explains that although important, some broad-spectrum antibiotics may kill

necessary bacteria in the gastro-intestinal tract. " Once these bacteria are

killed, other harmful bacteria occupy their place, leading to infection, " he

says.

The following are commonly prescribed medications that at times result in

undesirable side effects:

Tetracycline:

An important antibiotic, tetracycline can interfere with the formation of

the teeth and bones of a foetus if taken by a pregnant mother. The drug can

also be passed to babies through breast milk.

Chloramphenicol:

This antibiotic can cause irreversible and reversible aplastic anaemia if

taken for long periods. It is reserved for the treatment of life-threatening

bacterial infections like typhoid fever.

Penicillin:

If given penicillin, some patients experience hypersensitivity. They get

rashes and life-threatening anaphylactic shock.

Anti-malarials:

Murichu explains that, with anti-malarials, certain people may experience an

allergic complication that presents itself as a rash, itching,

gastro-intestinal disturbances and inability to breath. Quinine can lead to

cardiac arrhythmia (abnormal heartbeat) even at normal dosages. " In most

dispensaries, " Murichu explains, " they do not give chloroquin injections or

quinine infusions because they may not be prepared to handle the resulting

side effects. "

Cortico-steroids:

Meant to suppress the symptoms of severe inflammatory conditions, allergies,

asthma, organ rejection, etc, steroids can have frightening side effects in

large dosages, or if taken over long periods. Complications include

diabetes, brittle bones and lowered body immunity.

Paracetamol:

In excessive dosages, paracetamol has caused liver damage, life-threatening

complications and death.

Cough syrups:

Dr Nyikal, a paediatrician, explains that certain cough syrups contain

codeine " which can interfere with a baby's breathing " .

Anti vomiting drugs:

Drugs meant to stop a child's vomiting can cause severe central nervous

system reactions.

Anti-diarrhoeas:

These can cause severe abdominal distension (swelling) in a baby. Advises

Nyikal: " Give (your baby) fluids to replace lost water. "

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