With altered organ-functions, the effects and efficient removal of drugs is affected in elderly. Elderly are more likely to experience adverse effects of drugs. They may not be able to tolerate full doses of drugs.
Medicine may exhibit abnormal responses in the elder age group. For example, Diazepam (a sedating drug) may cause prolonged sleep and behavioral problems.
Generally metabolism of drugs and excretion by kidneys is reduced due to age resultant reductions in their function and hence dose adjustments are needed for several drugs. Liver blood flow is also decreased. Elderly have low total body water so drug distribution is affected. Serum albumen levels (which allows binding of drug) decrease and total body fat increases with age. Distribution of fat is on abdomen and there is thinning of legs and arms. These changes result in altered drug metabolism.
Finally, elderly people suffer from a number of diseases at a time and hence they take many drugs which interact (adversely) with each other. Older patients are likely to cause dosage errors due to forgetfulness, poor vision and hearing problems. These aspects need to be addressed by a conscientious prescriber.
Note: It is important to understand that a healthy old person is different from diseased old person. Drug related changes are minimal in the former gruop.
Always try non-drug treatments methods for trivial ailments.
Treatment should be started with lower than adult doses. Dose increments should be gradual.
As far as possible number of medicines be kept minimal. This improves compliance.
A family member should be asked to bring all medications at each visit and instructions are taken again for efficient management.
Errors in taking correct/exact doses of drugs may be due to physical restrictions such as tremor, limited joint movements and visual problems. Liquid drugs to be taken as 1-2 teaspoonful may not be taken correctly by elderly because of above reasons.
Cataract formation may diminish vision and thus. labels should be large enough for patients to see instructions clearly.
Extreme care and caution is needed in the use of following drug-groups. Anticoagulants: Haemotoma (blood collections) may form even after a minor fall if doses of anticoagulants are not regulated.
Antiglaucoma drugs: TIMOLD eye drops can be absorbed and cause slowing of pulse and fall in BP. Loss of appetite and weight is noted with the use of acetazolamide.
Pain relievers: Meperidine or pethidine may cause excitation and confusion in elderly. Paracetamol is safe. Other anti-inflammatory analgesics may worsen kidney function. D-propoxyphene may cause drowsiness.
Cough and cold remedies: They cause dryness, hesitancy of urination, constipation, fall or rise in BP and confusion.
Antivomiting drugs: Prochlorperazine and metocopramide may induce abnormal movements (dyskinesia).
Antipsychotics and antidepressants may cause difficulty in swallowing due to dryness of the mouth.
Antihypertensive drugs such as calcium channel blockers may cause swelling of feet and diuretics (thiazides) may not be useful in this case. Low dose thiazide alone have excellent BP reducing effect because of gradual fall in BP over days. Propranolol like drugs may be more hazardous in older patients with lung problems (particularly when they are smokers or ex-smokers). Alpha blockers (prazosin) are useful in high BP and cause dizziness or a person may actually faint on standing up. This is particularly true when thiazides are also given.
Once a drug is initiated a close watch is kept on drug induced adverse effects which may be subtle and evade detection.
Some preferred alternative drugs for elderly.