Medication errors can take myriad forms. Some common types of mistakes in medication are described below.

• Prescribing: Errors in prescribing include irrational, inappropriate, and ineffective prescribing, underprescribing and overprescribing (prescribing faults) and errors in writing (illegible prescription).
•  Omission errors: Failure to give a scheduled medication dose
• Incorrect timing: Medications should be administered at their scheduled times; failure to give a medication dose on time may cause either underdosing or overdosing. Food may also alter the absorption of some medications.
• Incorrect duration: Taking medications for shorter or longer duration than has been prescribed.
• Administration errors: Improper route of administration, giving the drug to the wrong patient, giving an extra dose of the drug, or administering drugs that are given IV at the incorrect rate, which may cause severe adverse drug reactions.
• Use of inappropriate abbreviations, confusion of metric and other dosing units
• Confusion between sound-alike drug names
• Prescribing contraindicated drugs.
• Monitoring errors: Failure to follow-up or to consider the patient’s liver and renal function or allergies or potential for drug-drug or drug-food interactions or not reviewing repeat prescriptions.
• Compliance errors: Not adhering to the protocol or rules or dispensing and prescribing medications • Expired product: Use of expired medications may occur because of their improper storage.