Popping your pills at the wrong time can seriously undermine their effectiveness

How and when we take prescribed drugs can make a huge difference to their effectiveness. When we swallow a pill or stick on a medicinal patch, the amount of drug in our bloodstream rises, until it reaches the required 'therapeutic" level. How long this lasts depends on how quickly our bodies excrete the drug, so subsequent doses are timed to keep levels topped up. Some drugs, such as HRT, last for 24 hours, so one tablet a day is enough. But others pass through the body more quickly and need to be taken several times a day.

Timing can be key

Your GP will often leave the choice of when to take your once-daily tablets up to you, but some tablets are best taken at specific times...

• Some cholesterol-lowering tablets (statins), such as Simvastatin, work best when taken at night; others, such as Atorvastatin, can be taken at anytime
• Steroids are often prescribed to be taken in the morning, as this has less effect on the body's natural steroid production
• If your joints are painful or stiff on waking, taking a long-acting painkiller before bed could alleviate your symptoms the next morning
• To work properly and prevent irritation, bone- building bisphosphonate drugs, such as Alendronate, must be taken firt thing on an empty stomach, followed by 30 minutes in an upright position before any drink or food (you can move, just don't bend over).

Before or after food?

Some pills need to be taken specifically before or after food, either because stomach acid destroys some medicines and stops them working, or because food in your stomach protects against side effects, such as nausea. If you take antacids for indigestion, emember that they contain magnesium, calcium or aluminium, which can block some drugs. Antacids may also affect tablets which have coatings designed to dissolve once they have passed through the stomach. What you eat can also affect how drug is absorbed. For example, calcium in dairy can interfere with tetracycline antibiotics for acne, so take these on an empty stomach.
Substances in tea, coffee and wine can prevent iron tablets from being absorbed, while Vitamin C in fruit juice actively encourages the body to absorb and use iron. Even if your medicine has been absorbed, food and drink can still affect the way it works.
Grapefruit interferes with the action of cholesterol-lowering statins, calcium-channel blockers for raised blood pressure, and many other medicines. And alcohol can increase drowsiness if taken with drugs that have sedative side effects, or even make you vomit if you're taking the antibiotic, metronidazole.

Mixing meds

Medicines prescribed together shouldn't necessarily be taken together, as they may not work as well. As mentioned before, antacids can affect many medicines, and calcium tablets shouldn't be taken at the same time as tetracycline antibiotics.

How often:
Twice daily: roughly every 12 hours
Three times daily: every eight hours
Four times daily: every six hours