Top 20 Prescription Errors Doctors Must Avoid

1. Ignoring Patient Allergies and Previous Adverse Drug Reactions (ADRs)
One of the most preventable and dangerous mistakes is prescribing a medication that a patient is allergic to or has had a bad reaction to in the past.

• Always review the allergy section in the patient’s medical record.
• Ask explicitly about any known drug allergies during consultation, even if it’s a follow-up.
• Train clinic staff to flag these alerts clearly, especially for antibiotics, NSAIDs, and contrast agents.
• Do not rely solely on EHR alerts—cross-check manually when in doubt.
• Document reactions precisely (e.g., "anaphylaxis" vs. "nausea") to prevent inappropriate allergy labels that limit future options.

2. Prescribing Without Reviewing Renal or Hepatic Function
Renal and hepatic clearance are critical in drug metabolism. Prescribing full doses in patients with impaired function can lead to toxicity.

• Always check creatinine clearance (not just serum creatinine) in elderly patients.
• Be cautious with nephrotoxic drugs like aminoglycosides, vancomycin, or NSAIDs.
• Use dose-adjusting calculators or hospital software to fine-tune dosages in liver or kidney disease.
• For drugs like digoxin or lithium, monitor plasma levels frequently.
• Avoid long-acting benzodiazepines or opioids in cirrhotic patients.

3. Using Ambiguous Abbreviations or Illegible Handwriting
Illegible prescriptions are a root cause of dispensing errors. Even with electronic prescriptions, ambiguous shorthand creates confusion.

• Avoid abbreviations like “U” for units, “QD” for once daily, or “MS” which may mean morphine sulfate or magnesium sulfate.
• Use capital letters and print clearly if writing by hand.
• Always write the full drug name, dosage, frequency, route, and duration.
• Prefer “once daily” over “OD” and “every 6 hours” over “Q6H” for clarity.
• Encourage pharmacists to call and confirm any unclear orders.

4. Not Considering Drug-Drug Interactions
Polypharmacy is common, especially in older patients. Overlooking interactions can lead to dangerous outcomes.

• Be cautious with CYP450 inhibitors or inducers (e.g., erythromycin, rifampin).
• Common combinations to avoid:
  • Warfarin + NSAIDs → increased bleeding
  • ACE inhibitors + potassium supplements → hyperkalemia
  • SSRIs + tramadol → serotonin syndrome
• Always check for potential interactions using tools like Lexicomp, Micromedex, or hospital software.
• Review over-the-counter (OTC) and herbal medications as patients rarely report them.

5. Not Adjusting Doses for Special Populations
Children, the elderly, pregnant women, and lactating mothers require tailored dosing.

• Pediatric doses must be calculated using body weight or surface area, not "guesstimated."
• Geriatric patients have altered pharmacokinetics and are more sensitive to CNS effects—start low and go slow.
• Use pregnancy-safe classifications and avoid teratogenic drugs (e.g., isotretinoin, valproate).
• Cross-reference lactation compatibility if the mother is breastfeeding.

6. Prescribing Antibiotics Inappropriately
Overprescribing antibiotics fuels resistance and harms patients.

• Avoid antibiotics for viral infections like the common cold or influenza.
• Use narrow-spectrum antibiotics whenever possible.
• Follow local antibiograms to guide empirical therapy.
• Stop therapy if cultures show sensitivity to narrower or more appropriate options.
• Clearly mention duration—e.g., “Amoxicillin 500 mg TID for 7 days,” not “as needed.”

7. Ignoring the Route of Administration and Patient Capability
Prescribing the right drug via the wrong route is a practical and harmful error.

• Don’t prescribe tablets to patients with dysphagia unless crushable or available in liquid form.
• Avoid intramuscular injections in anticoagulated patients.
• Ensure patients on inhalers or eye drops know how to use them; poor technique can render treatment useless.
• Always clarify: is it oral, topical, IV, or sublingual?

8. Failure to Check the Latest Medication List
Patients may already be on medications prescribed by other providers or obtained elsewhere.

• Always reconcile medications during each visit.
• Cross-check what the patient is actually taking (bring the pillbox).
• Educate the patient to avoid duplication, such as two antihypertensives or two NSAIDs.
• Update records immediately if a medication is discontinued.

9. Ignoring Therapeutic Duplication
Some drugs belong to the same class and have similar effects. Prescribing two can double side effects with minimal benefit.

• Don’t combine ACE inhibitors with ARBs.
• Don’t use two SSRIs concurrently.
• Avoid dual antiplatelet therapy unless clearly indicated.
• Audit prescription history, especially when multiple specialists are involved.

10. Not Mentioning Frequency, Duration, or Refill Instructions
Incomplete prescriptions cause confusion at the pharmacy and errors in administration.

• Always include the number of days to be taken, not just dosage.
• Write clearly: “Metronidazole 500 mg TID x 7 days” instead of “Metronidazole 500 mg TID.”
• Mention whether the prescription is for acute use or requires follow-up.
• Refill instructions are crucial for chronic meds like insulin or antihypertensives.

11. Skipping Patient Education
Prescribing ends at counseling. Many adverse outcomes arise from patients not understanding how to take their medications.

• Explain dosing schedules, especially with tapering regimens like steroids.
• Warn about potential side effects that require urgent attention (e.g., angioedema with ACE inhibitors).
• Discuss food or drug interactions—e.g., avoid grapefruit juice with statins.
• Encourage adherence and explain what to do in case of missed doses.

12. Failing to Monitor High-Risk Medications
Some drugs demand close follow-up due to their narrow therapeutic index.

• Warfarin requires regular INR checks.
• Lithium needs plasma level monitoring and thyroid/kidney function tests.
• Methotrexate needs CBC, LFT, and renal function monitoring.
• Clozapine requires regular white cell count monitoring.
• Don’t assume follow-up labs will be ordered by someone else—document who is responsible.

13. Writing PRN Medications Without Indications
Prescribing “as needed” meds without specifying the indication or frequency leads to misuse.

• Avoid “Paracetamol 500 mg PRN” alone. Instead, write: “for headache, max 4 g/day.”
• PRN sedatives or analgesics should include maximum daily limits to prevent overdose.
• Clarify when the medication should be discontinued (e.g., after 3 days of use).

14. Ignoring Cost and Availability
Prescribing a drug that’s unaffordable or unavailable locally does more harm than good.

• Be mindful of generic equivalents—don't default to expensive brands.
• Ask about insurance coverage or cost barriers.
• Check formularies or hospital inventories if the patient will fill meds onsite.
• Always have an alternative plan in mind in case a drug is not stocked.

15. Failure to Discontinue Unnecessary Medications
Deprescribing is as vital as prescribing. Continuing drugs long after they are needed causes polypharmacy and side effects.

• Reassess proton pump inhibitors, antidepressants, antihistamines, and pain medications regularly.
• Post-hospitalization medications (e.g., enoxaparin, antibiotics) must be reviewed at follow-up.
• Use tools like STOPP/START criteria in geriatric patients to minimize drug burden.

16. Not Tailoring to Cultural or Religious Contexts
Some patients may decline certain drugs or routes due to beliefs.

• Gelatin-based capsules may be unacceptable to some religious groups.
• Fasting patients may not tolerate daytime dosing.
• Discuss these issues openly and offer alternatives.

17. Forgetting to Consider Pharmacogenetics (Emerging Area)
Not all patients metabolize drugs the same way. Although still evolving, pharmacogenomics is relevant in psychiatry, oncology, and cardiology.

• CYP2D6 variations affect codeine efficacy.
• TPMT deficiency can cause toxicity with azathioprine.
• Use testing when indicated, especially in high-risk scenarios.

18. Prescribing Look-Alike or Sound-Alike Drugs
Some drugs have similar names but vastly different actions.

• Examples:
  • Celebrex (celecoxib) vs. Celexa (citalopram)
  • Lamictal (lamotrigine) vs. Lamisil (terbinafine)
• Always double-check the spelling and indication before finalizing the prescription.

19. Failing to Account for Delayed Onset or Tapering Requirements
Not all drugs act immediately, and some require tapering.

• Antidepressants often take weeks—set expectations properly.
• Abruptly stopping steroids, beta-blockers, or benzodiazepines can cause withdrawal or rebound effects.
• Always mention tapering schedules if discontinuing.

20. Prescribing Controlled Substances Without Due Caution
Opioids, benzodiazepines, and stimulants need extra responsibility.

• Limit supply for acute conditions.
• Use state monitoring systems to track potential abuse.
• Discuss risks openly with patients.

Avoid prescribing long-term without a treatment agreement or clear justification