How strength, dosage form and label directions tell a patient how to take a drug
PTCB topic: Strengths, dosage forms, routes and administration
- Strength is drug per unit: mg per tablet, mg/5 mL or units/mL.
- Sublingual tablets dissolve under the tongue; ODTs dissolve on the tongue.
- Swallow extended-release products whole unless the label says otherwise.
- Volume per dose = dose ÷ concentration.
- Methotrexate 7.5 mg once weekly: 12 tablets of 2.5 mg per 28 days.
Key facts
- Nitroglycerin sublingual tablets (Nitrostat) dissolve under the tongue or in the buccal pouch without being swallowed; no more than 3 tablets in 15 minutes.
- Volume per dose = dose ÷ concentration, so 600 mg of a 400 mg/5 mL suspension is 7.5 mL.
- U-100 insulin has 100 units per mL, so a 3 mL U-100 pen holds 300 units.
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- Tamsulosin capsules are not crushed, chewed or opened, and metformin extended-release tablets are swallowed whole.
- Omeprazole delayed-release capsules may be opened and the pellets sprinkled on a tablespoon of applesauce, then swallowed right away without chewing.
- Alendronate is taken on rising with 6 to 8 oz of plain water, at least 30 minutes before the first food, drink or medication.
- Oral methotrexate for rheumatoid arthritis is dosed once weekly, so a 28-day supply of 7.5 mg weekly is 12 tablets of 2.5 mg.
Quick check1 question · 2 more at the end
A patient picks up nitroglycerin 0.4 mg tablets (Nitrostat) for angina. According to the label, how is one tablet taken at the first sign of an attack?
Correct answer: C.
Nitrostat is a sublingual tablet: at the onset of an attack one tablet goes under the tongue or in the buccal pouch and is allowed to dissolve without swallowing. One more tablet may be used every 5 minutes, but the label recommends no more than 3 tablets within 15 minutes. Strengths are 0.3 mg, 0.4 mg and 0.6 mg.
A Swallowing the tablet is the wrong route; the label directs the patient to let it dissolve without swallowing.
B Chewing and swallowing treats it like an ordinary oral tablet, but Nitrostat is a sublingual dosage form.
C Correct: Nitrostat is a sublingual tablet placed under the tongue or in the buccal pouch and allowed to dissolve without swallowing.
D Nitrostat is not a tablet for oral solution; the label says to place it under the tongue or in the buccal pouch.
Full lesson
Each part starts with its main idea. Open a part when you want the details.
The short answer: Strength is the amount of drug per unit, such as mg per tablet, mg/5 mL or units/mL. The dosage form sets the route: sublingual tablets dissolve under the tongue, ODTs on the tongue, patches on the skin. Extended-release products are swallowed whole unless the label says otherwise, and dose ÷ concentration gives the volume per dose.
1 What do the strength and dosage form tell you?The strength and the dosage form together tell you how much drug is in each unit and how it enters the body. 1 min
The strength and the dosage form together tell you how much drug is in each unit and how it enters the body. The 2026 PTCE outline groups strengths, dosage forms, routes, special handling, administration directions and duration of therapy in area 1.4, and marks the area as partly calculation-based.
Strength is the amount of active drug per unit. It may be per tablet (Nitrostat 0.4 mg), per volume (an oral suspension labeled 400 mg/5 mL) or in units (insulin U-100 = 100 units per mL). Many drugs come in several strengths, so the strength on the order must match the product you pick.
2 Which route goes with which dosage form?Each dosage form is built for one route, and the label explains exactly how to use it. 1 min
Each dosage form is built for one route, and the label explains exactly how to use it.
| Dosage form | Route | Label direction |
|---|---|---|
| Sublingual tablet (Nitrostat) | Under the tongue | Let it dissolve; do not swallow it |
| Orally disintegrating tablet (ondansetron ODT) | On the tongue | Dry hands, peel back the foil, swallow with saliva |
| Extended-release tablet (metformin ER) | Swallowed | Swallow whole; never crush, cut or chew |
For Nitrostat, one tablet goes under the tongue or in the buccal pouch at the first sign of angina. One more may follow every 5 minutes, but the label recommends no more than 3 tablets in 15 minutes.
3 When can a tablet or capsule be crushed, cut or opened?Assume that a modified-release product must stay intact unless its own label allows otherwise. 1 min
Assume that a modified-release product must stay intact unless its own label allows otherwise. Each label below states its own rule, so check the label rather than guess.
- Tamsulosin capsules: not crushed, chewed or opened.
- Metformin extended-release tablets: swallowed whole, never crushed, cut or chewed.
- Omeprazole delayed-release capsules: the label gives an exception. Open the capsule, empty the pellets onto a tablespoon of soft applesauce that is not hot, and swallow at once with cool water, without chewing the pellets.
4 Which timing and food directions come from the label?Timing and food directions protect absorption or reduce side effects, and they come straight from the label. 1 min
Timing and food directions protect absorption or reduce side effects, and they come straight from the label.
- Alendronate (Fosamax): on rising, with 6 to 8 oz of plain water. Take it at least 30 minutes before the first food, drink or medication, and do not lie down for 30 minutes.
- Metformin extended-release: once daily with the evening meal.
- Tamsulosin: about half an hour after the same meal each day.
5 How do you do the dose and duration math?Most dose math in this area is one division and one multiplication. 1 min
Most dose math in this area is one division and one multiplication.
- Volume per dose = dose ÷ concentration. For 600 mg from 400 mg/5 mL: 600 × 5 ÷ 400 = 7.5 mL.
- Tablets per dose = dose ÷ tablet strength. A 40 mg dose from 10 mg tablets is 4 tablets.
- Quantity = units per dose × doses per day × days. Check the frequency first. Methotrexate 7.5 mg (three 2.5 mg tablets) once weekly is 12 tablets for 28 days, not 84.
6 What the technician doesThe technician picks the right strength and form, counts the right quantity for the duration, and adds auxiliary labels that match the product label. 1 min
The technician picks the right strength and form, counts the right quantity for the duration, and adds auxiliary labels that match the product label. A question the label does not answer, such as whether a patient may crush a tablet, goes to the pharmacist.
Common mistakes
The traps students fall into most. Read these before you practice.
Watch out: Methotrexate once weekly, not once daily.
Watch out: Peel back the foil of an orally disintegrating tablet, not push the tablet through it.
Watch out: Divide by the concentration per 5 mL, not per 1 mL, when a suspension is labeled mg/5 mL.
Watch out: Swallow extended-release tablets whole, not cut, crushed or chewed.
How to remember it
Read every order like a recipe with five parts, always in the same order.
What (strength), shape (dosage form), where (route), when (timing and food), how long (duration).
Self-check:
- Can you name the route for a sublingual tablet and an ODT?
- Can you name one capsule that may be opened and one that may not?
- Can you find the mL per dose for any mg/5 mL suspension?
Show answers
- Sublingual: under the tongue. ODT: on the tongue.
- A sublingual tablet dissolves under the tongue and is not swallowed.
- An ODT dissolves on the tongue and is swallowed with saliva.
- Omeprazole delayed-release may be opened; tamsulosin may not.
- Omeprazole pellets may go on a tablespoon of applesauce, swallowed without chewing.
- Tamsulosin capsules are not crushed, chewed or opened.
- mL per dose = dose ÷ concentration.
- Example: 600 mg from a 400 mg/5 mL suspension.
- Multiply: 600 × 5 = 3,000.
- Divide: 3,000 ÷ 400 = 7.5 mL.