Dosage: How to Take Medicines Safely and Exactly

Getting the dose right matters. Too little may not help; too much can hurt. This page gives clear, practical steps to read labels, measure liquids, calculate weight-based doses for kids, and handle missed or extra doses without confusing medical jargon.

Read the label like a pro

Start by checking three things: amount (mg, mcg, IU), frequency (how often), and route (oral, topical, inhaled). Abbreviations you'll see: BID = twice a day, TID = three times, QHS = at bedtime, PRN = as needed. If a prescription says "take 1 tablet 2 times daily," that means morning and evening, not two tablets at once.

Watch units. milligrams (mg) and micrograms (mcg) are not the same—1,000 mcg = 1 mg. Insulin uses units (U or IU). If labels look unclear, call the pharmacy before taking anything.

Measure liquids and convert when needed

Use the measuring tool that comes with the medicine: oral syringe, dropper, or dosing cup. Kitchen teaspoons are unreliable—one spoon can vary by a teaspoon or more. Example: a syrup reads 250 mg/5 mL and your child needs 125 mg. That’s 2.5 mL. Do the math: dose (mg) ÷ concentration (mg/mL) = mL to give.

For weight-based dosing common in kids and some adults, prescribers may say something like 10 mg/kg. If a 15 kg child needs 10 mg/kg, that’s 150 mg total. If the liquid is 50 mg/5 mL, then 150 mg = 15 mL. Double-check the math with the pharmacist if you’re unsure.

Some meds require titration (start low, increase slowly) or tapering off. Never stop or change doses for antidepressants, steroids, or seizure meds without talking to your doctor—stopping suddenly can cause withdrawal or worse.

Kidneys and liver matter. Older adults or people with reduced kidney or liver function often need lower doses. If you have chronic kidney disease or liver disease, mention it when you get the prescription so the prescriber can adjust the dose.

Avoid mixing meds with alcohol or certain supplements without checking interactions. Some combinations boost side effects or change how much of a drug your body absorbs. Use an interaction checker or ask your pharmacist for a quick check.

If you miss a dose, take it as soon as you remember unless it’s almost time for the next one—then skip the missed dose. Never double up to make up for a missed pill (unless your prescriber tells you otherwise).

If you suspect an overdose or severe reaction (trouble breathing, fainting, severe drowsiness, seizures), call emergency services right away and contact your local poison control center. It’s better to be safe.

Final practical tip: keep a medication list with names, doses, and times. Bring it to every doctor or pharmacy visit. When in doubt, call your pharmacist—they deal with dosage questions all day and can clear up confusion fast.