Ever wondered why you are told by a health worker to take a particular medicine on an empty stomach ( 1 hour before food / 2 hours after eating food) or that you should eat food before taking a certain medication? This most times relate to absorption of such a medicine when taken in presence or absence of food in the stomach. Whereas for some medicines absorption is not affected by food in the Stomach, the extent and rate of absorption of some medicines can be affected by food in the stomach. For a medicine to work properly, it has to be absorbed, distributed , metabolised in the body before it is excreted from the body. Allow me share with you some of the common medicines whose absorption is affected by food.
✓ Food reduces extent of absorption of Isoniazid ( used as TB medication) and Ketoconazole ( used to treat fungal infections).
✓ Food reduces rate of Absorption and amount of absorbed penicillins, rifampicin and tetracyclines.
✓ Food decreases extent of absorption of Atenolol ( used to lower blood pressure).
✓Food decreases rate of absorption and amount absorbed of cephalosporins like cephalexin.
✓ Food delays absorption of Digoxin (for heart failure )but total amount not affected
✓For some drugs like warfarin (for dissolving blood clots), no important changes in absorption occurs with food in the Stomach but much absorption in the intestines. So if vomiting occurs within 30 minutes repeat the dose.
✓ For some medicines food increases absorption forexample Griseofulvin absorption is enhanced by concurrent ingestion of fatty meal
✓Mebendazole – extent of absorption increased when taken with fatty meal.
✓ For Phenytoin – food increases both extent and rate of absorption
✓ Absorption of propranolol , Metoprolol, Labetalol and hydralazine is greater in fed than fasted state..
✓Nitrofurantoin Absorption is enhanced by fatty meal.
✓ Food delays absorption of sulphonamides but the total amount is not reduced
✓ Friends, allow me share further with you that it is not only about presence of food in the stomach but the motility of the gut and rate at which the control on the stomach opening into the small intestines they call pyloric sphincter are very important. Some medicines can delay gastric emptying while others can prolong it. Forexample antihistamines (like cetrizine) , antimuscarinics ( like Atropine) chloroquine, phenothiazines ( like promethazine commonly know as intamine/ phenergan) , opioid analgesics like morphine, pethidine , sympathomimetics like dopamine and ganglion blocking drugs like Hexamethonium decrease gastric emptying rate.
While anticholinergics ( like Neostigmine, physostigmine) cisapride, Dopamine antagonists ( like metoclopramide/ plasil, domperidone) , sodium bicarbonate, Isoniazid and Sumatriptan increase gastric emptying rate.
✓Reduced gastric emptying slows transfer of the drug to absorbing surfaces of small intestines and hence slowed absorption. This may be disadvantageous when you want a rapid onset of action like say when one is in pain and you give an analgesic ( a medicine that takes away pain) or you want to sleep and hypnotic needed. Such medicines are therefore administered during fasting periods where gut motility is also high.
✓Given the varied responses on absorption of medicines when food is present or absent in the stomach, it is important to read the label and information leaflet of every medicine. It is much better to consult a health worker and do not self medicate. Hope you have been enlightened by this sharing. Thanks for your attention.
In case of Cough, flu and sore throat, look for Elocof at nearest Pharmacy, drug shop and clinic across Uganda. ELOCOF is specially formulated by Dr Lutoti for children and adults, manufactured by Eloipharm (u) Ltd . Elocof is effective, affordable and authorised by National Drug Authority. Because Elocof improves digestion, you may feel hungry so fast after taking it. Therefore, eat food after taking ELocof.
Let us share with others to be informed and save lives. Stay blessed.
Dr Lutoti of ELOCOF.
For inquiries, call 0782764180/ 0758329111