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Introduction
1. Medications
1.1 Generic names and brand names
1.2 Classification of medications
1.3 Drug interactions and contraindications
1.4 Medications by organ system
1.5 Drug strengths, dose, and dosage forms
1.6 Routes of administration and special handling of drugs
1.7 Medication side effects, adverse effects and allergies
1.8 Indications of medications and dietary supplements
1.9 Drug stability
1.10 Narrow therapeutic index (NTI) medications
1.11 Pharmaceutical incompatibilities
1.12 Proper storage of medications
1.13 Vaccine types and schedules
2. Patient safety and quality assurance
3. Order entry and processing
4. Federal requirements
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1.10 Narrow therapeutic index (NTI) medications
Achievable PTCE
1. Medications

Narrow therapeutic index (NTI) medications

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Therapeutic index (TI) or therapeutic ratio

The ratio of the dose that produces toxicity to the dose needed to produce the desired therapeutic response. The following formula gives it.

TI = TD50/ED50,

TD50 is the toxic dose, and ED50 is the effective dose for 50% of the population tested.

The higher the Therapeutic Index, the safer the drug. However, drugs with a narrow TI, also known as NTI drugs or Narrow Therapeutic Range (NTR) drugs, need to be meticulously monitored. This is because the difference between their therapeutic and toxic doses is minimal.

Common drugs with a narrow therapeutic index

  • Digoxin

  • Lithium

  • Phenytoin

  • Theophylline

  • Warfarin

  • Levothyroxine

  • Carbamazepine

  • Cyclosporine

  • Ethosuximide

  • Procainamide

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