The science and activities relating to the detection, assessment, understanding, and prevention of adverse effects or any other medicine/vaccine-related problems. (WHO, 2002)
Goal: improve patient safety by monitoring medicines in real-world clinical practice beyond clinical trials.
A harmful and unintended response to a medicine at normal doses used for prophylaxis, diagnosis, or therapy. Causality is implied.
Any injury resulting from medical intervention related to a drug. Includes ADRs and errors. Causality is NOT implied — may or may not be preventable.
Any preventable event that may cause or lead to inappropriate medication use or patient harm while the medication is in control of the healthcare professional.
| Type | Name | Mechanism | Examples | Frequency |
|---|---|---|---|---|
| A | Augmented | Dose-related, predictable, extension of pharmacological effect | Bradycardia from beta-blockers, hypoglycaemia from insulin, bleeding from warfarin | ~80% of all ADRs |
| B | Bizarre | Unpredictable, not dose-related, immune-mediated or idiosyncratic | Penicillin anaphylaxis, SJS from carbamazepine, halothane hepatitis | Rare but severe |
| C | Chronic/Continuous | Related to long-term cumulative dose | Cushingoid features from steroids, tardive dyskinesia from antipsychotics, analgesic nephropathy | Long-term use |
| D | Delayed | Appear after prolonged latency | Carcinogenesis (alkylating agents), teratogenesis (thalidomide), tardive dyskinesia | Long latency |
| E | End of Use | Withdrawal reaction | Opioid withdrawal, benzodiazepine withdrawal, corticosteroid withdrawal, rebound hypertension from clonidine | On stopping |
| F | Failure of Therapy | Unexpected therapeutic failure | Antibiotic resistance, oral contraceptive failure with enzyme inducers, subtherapeutic drug levels | Variable |
A standardised questionnaire of 10 yes/no/unknown questions used to establish the probability that an ADR is caused by the suspected drug.
Note: scores <1 = doubtful; 1–4 = possible; 5–8 = probable; ≥9 = definite.
| # | Question | Yes | No | Unknown |
|---|---|---|---|---|
| 1 | Are there previous conclusive reports of this reaction? | +1 | 0 | 0 |
| 2 | Did the adverse event appear after the suspected drug was given? | +2 | −1 | 0 |
| 3 | Did the adverse reaction improve when the drug was discontinued or a specific antagonist given? | +1 | 0 | 0 |
| 4 | Did the adverse reaction reappear when the drug was re-administered? | +2 | −1 | 0 |
| 5 | Are there alternative causes that could have caused the reaction? | −1 | +2 | 0 |
| 6 | Did the reaction reappear when a placebo was given? | −1 | +1 | 0 |
| 7 | Was the drug detected in blood/other fluids in concentrations known to be toxic? | +1 | 0 | 0 |
| 8 | Was the reaction more severe when the dose was increased or less severe when it was decreased? | +1 | 0 | 0 |
| 9 | Did the patient have a similar reaction to the same or similar drug in any previous exposure? | +1 | 0 | 0 |
| 10 | Was the adverse event confirmed by any objective evidence? | +1 | 0 | 0 |
| Total Score Interpretation | ≤0 Doubtful | 1–4 Possible | 5–8 Probable | ≥9 Definite | |||
The WHO global database of Individual Case Safety Reports (ICSRs). Maintained by Uppsala Monitoring Centre (UMC). Contains >30 million reports.
The US FDA's safety reporting portal for healthcare professionals and consumers. Reports go to FAERS (FDA Adverse Event Reporting System).
UK scheme for reporting suspected ADRs. Open to healthcare professionals AND patients. Reports feed into MHRA database and VigiBase.
Saudi Food and Drug Authority Pharmacovigilance Centre. National ADR reporting via SFDA Yellow Card system / Nar portal.
Dubai Health Authority (DHA) Pharmacovigilance Unit and Ministry of Health and Prevention (MOHAP) ADR reporting system.
Ministry of Public Health Qatar — National Pharmacovigilance Centre with its own ADR reporting portal.
| Element | Details Required |
|---|---|
| Patient | Age/sex/weight, relevant medical history, comorbidities |
| Suspect Drug | Generic name, brand name, dose, route, indication, batch number if available |
| Reaction | Description, onset date, duration, MedDRA-coded preferred term |
| Outcome | Recovered / recovering / not recovered / fatal / unknown; sequelae |
| Reporter | Name, profession, contact details, country |
| Dechallenge | Did reaction improve on stopping drug? (Yes/No/N/A) |
| Rechallenge | Did reaction recur on restarting drug? (Yes/No/N/A) |
A signal is information arising from one or more sources suggesting a new potentially causal association between an intervention and an event. Signal detection uses statistical methods (e.g., Proportional Reporting Ratio — PRR) on aggregate ICSR data.
Signals require validation, prioritisation, and assessment before action (e.g., label update, Dear Healthcare Professional letter, market withdrawal).
RUCAM scale (Roussel Uclaf Causality Assessment Method) — standardised causality tool for DILI.
N-acetylcysteine (NAC) — antidote for paracetamol toxicity; most effective within 8 hours; still beneficial up to 24h.
Monitor: ALT, AST, ALP, bilirubin, INR (synthetic function).
Hy's Law: ALT >3× ULN + bilirubin >2× ULN = serious hepatotoxicity risk, consider drug withdrawal.
Monitor: serum creatinine, eGFR, urine output, electrolytes (K+, Na+), urine microscopy.
KDIGO criteria for AKI: creatinine rise ≥26.5 µmol/L in 48h OR ≥1.5× baseline in 7 days OR urine output <0.5 mL/kg/h for ≥6h.
Normal QTc: <440ms (men), <460ms (women)
QTc >500ms — significantly increased risk of Torsades de Pointes (TdP). Withhold offending drug.
Additional risk factors: hypokalaemia, hypomagnesaemia, bradycardia, female sex, heart disease.
Reference: CredibleMeds (Arizona CERT) — categorises QTc risk as Known/Conditional/Possible risk.
| Drug | Class | CredibleMeds Risk | GCC Relevance |
|---|---|---|---|
| Chloroquine | Antimalarial | Known Risk | Widely available; used in GCC for malaria prophylaxis |
| Hydroxychloroquine | Antimalarial/DMARD | Known Risk | Rheumatology use common in GCC |
| Haloperidol IV | Antipsychotic | Known Risk | ICU sedation use |
| Erythromycin IV | Macrolide | Known Risk | Gastric motility use |
| Azithromycin | Macrolide | Known Risk | High OTC use in some GCC countries |
| Moxifloxacin | Fluoroquinolone | Known Risk | TB treatment protocols in GCC |
| Methadone | Opioid | Known Risk | Pain clinics, addiction medicine |
| Quetiapine | Antipsychotic | Conditional Risk | High psychiatric use; OD risk |
| Ondansetron >32mg | Antiemetic | Known Risk | IV use in oncology/PONV |
| Domperidone | Antiemetic/prokinetic | Known Risk | Available OTC in some GCC states |
Requires a serotonergic agent PLUS one of:
Atypical antipsychotic. Mandatory FBC monitoring: weekly for 18 weeks, then monthly. Stop if neutrophils <1.5×10⁹/L. Never rechallenge if ANC <0.5.
Antithyroid drugs. Risk ~0.1-0.5%. Educate patients to report sore throat/fever immediately and stop drug. Check FBC urgently.
Widely used analgesic/antipyretic in GCC and Arab world. Banned in some countries due to agranulocytosis risk. Monitor FBC with prolonged use.
Hepatic enzymes responsible for metabolism of ~75% of drugs. Interactions occur via inhibition (increased drug levels) or induction (decreased drug levels).
Inhibitors (increase substrate levels):
Inducers (decrease substrate levels):
| Drug 1 | Drug 2 | Interaction Type | Consequence | Action |
|---|---|---|---|---|
| Warfarin | NSAIDs | PK + PD | Serious bleeding risk | Avoid; use paracetamol if analgesia needed |
| Warfarin | Antibiotics (metronidazole, co-trimoxazole) | PK (CYP2C9 inhibition) | INR elevated, bleeding risk | Monitor INR closely, reduce warfarin dose |
| Methotrexate | NSAIDs | PK (reduced renal clearance) | Methotrexate toxicity — bone marrow suppression | Avoid combination; use alternative analgesic |
| Lithium | NSAIDs | PK (reduced renal clearance) | Lithium toxicity (tremor, confusion, renal failure) | Avoid; use paracetamol; monitor lithium levels |
| Lithium | ACE inhibitors | PK (sodium depletion) | Lithium toxicity | Monitor lithium levels; consider dose reduction |
| SSRIs | MAOIs | PD (serotonergic) | Serotonin syndrome — potentially fatal | Contraindicated; 2-week washout required |
| Antipsychotics | QTc-prolonging drugs | PD (additive QTc) | Torsades de Pointes, cardiac arrest | Avoid combination; ECG monitoring |
| Statins | Macrolides (clarithromycin) | PK (CYP3A4 inhibition) | Rhabdomyolysis risk (statin toxicity) | Temporarily stop statin or use azithromycin |
The process of comparing a patient's medication orders to all medications the patient has been taking to avoid discrepancies. Nurses play a critical role at admission, transfer, and discharge.
Comprehensive DDI database; gold-standard for clinical use; severity ratings A–X.
IBM/Truven database; contraindication/major/moderate/minor severity classification.
Used across GCC; appendix 1 lists interactions; freely available in UK; used in many GCC nursing curricula.
0.8 – 2.0 nmol/L (heart failure target 0.5–1.0 nmol/L)
Digoxin-specific antibody fragments (DigiFab) for severe toxicity
Prophylaxis (maintenance): 0.4–1.0 mmol/L
Acute mania: 0.8–1.2 mmol/L
Sample: 12 hours after last dose (trough)
>1.5 mmol/L: mild–moderate toxicity
>2.0 mmol/L: severe toxicity — hospitalise
Dehydration, low-sodium diet, NSAIDs, ACE inhibitors all increase lithium toxicity risk.
Pre-dose trough: gentamicin <2 mg/L; amikacin <10 mg/L
Post-dose peak: gentamicin 5–10 mg/L; amikacin 20–30 mg/L
Sample timing: trough within 30 min before dose; peak 60 min after IV infusion end.
Hartford nomogram used; single sample at 6–14h post-dose. Target: concentration falls below minimum threshold before next dose.
| Parameter | Target |
|---|---|
| AUC/MIC (MRSA MIC 1 mg/L) | 400–600 mg·h/L |
| Old trough target (if AUC not available) | 15–20 mg/L (serious infections) |
| Sampling | Two-point Bayesian (pre-dose + 1–2h post-infusion) preferred |
| Renal monitoring | SCr every 48–72h; more frequently if unstable |
| Infusion | Rate ≤10 mg/min to avoid Red Man Syndrome (vancomycin flushing syndrome) |
Per ASHP/IDSA/SIDP 2020 Consensus Guidelines:
| Drug | Therapeutic Range | Key Monitoring | Special Note |
|---|---|---|---|
| Phenytoin | 10–20 mcg/mL (total) | Levels, FBC, LFTs | Zero-order kinetics — small dose increase = large level rise. Highly protein-bound — check free levels in hypoalbuminaemia. |
| Theophylline | 10–20 mg/L | Levels, HR, ECG | Narrow range; toxicity: arrhythmia, seizures. Many DDIs (CYP1A2). |
| Ciclosporin | Transplant-specific (100–400 ng/mL) | Trough levels, renal function, BP | Individualised targets by transplant type and time post-transplant. |
| Tacrolimus | Transplant-specific (5–15 ng/mL) | Trough levels, renal function, glucose | Diabetogenic; more potent CNI than ciclosporin. CYP3A4 substrate. |
| Methotrexate | Varies by protocol | FBC, LFTs, renal function monthly | Folinic acid rescue for high-dose. NSAIDs, trimethoprim increase toxicity. |
Saudi Food and Drug Authority. National Pharmacovigilance Centre. Online portal: Nar system. Yellow Card equivalent. Healthcare professionals and consumers may report. SFDA publishes drug safety alerts.
Dubai Health Authority (DHA) for Dubai Emirate. Ministry of Health and Prevention (MOHAP) for federal UAE. Both have ADR reporting portals. DHA nursing competency frameworks include pharmacovigilance.
Ministry of Public Health Qatar. National pharmacovigilance programme. ADR reporting integrated into Hamad Medical Corporation safety systems. MOPH issues drug safety communications.
NSAIDs (particularly diclofenac, ibuprofen) are widely available OTC in many GCC countries. High self-medication prevalence, especially for musculoskeletal pain. Risks: GI bleeding, renal impairment, cardiovascular events, masking fever in infections. Nurses should counsel patients to use lowest effective dose for shortest duration.
| Herb | Arabic Name | Interaction / Risk |
|---|---|---|
| Black seed (Nigella sativa) | Habbatus sauda / حبة سوداء | May enhance anticoagulant effect of warfarin; hypoglycaemia with antidiabetics |
| Fenugreek (Trigonella foenum-graecum) | Hilba / حلبة | Anticoagulant effect; hypoglycaemic; may affect drug absorption |
| Ginseng | Ginseng / جينسنج | Reduces warfarin efficacy; interacts with MAOIs; hypoglycaemia risk |
| St John's Wort | Hypericum / عشبة سانت جون | CYP3A4 inducer — reduces levels of cyclosporin, warfarin, oral contraceptives, antiretrovirals |
| Sabbar (Aloe vera laxative) | صبار | Anthraquinone laxatives — electrolyte imbalance; hepatotoxicity with high doses; potentiates digoxin toxicity via hypokalaemia |
A growing problem across GCC. Unregulated online pharmacies may supply substandard, counterfeit, or falsified medicines. Risks: incorrect dose, wrong active ingredient, microbial contamination, no patient-specific counselling. SFDA, DHA, and MOPH all have campaigns against counterfeit medicines. Nurses should advise patients to purchase from licensed pharmacies only.
Saudi Commission for Health Specialties (SCFHS) nursing examinations include pharmacology components: drug calculations, high-risk medications, ADR recognition, patient education, and safe medication administration.
Dubai Health Authority and Department of Health Abu Dhabi nursing frameworks require nurses to: recognise and document ADRs, report via official channels, counsel patients on drug safety, and participate in medication reconciliation.
During Ramadan (fasting from dawn to sunset), drug absorption, distribution, metabolism, and efficacy can be affected. Key nursing considerations:
Enter details of the suspected ADR. The tool calculates a Naranjo-based score and generates a reporting recommendation.