01
Pathophysiology of Dental Pain
Pain Mechanisms
Dental pain is mediated through the nerve fibers of the trigeminal nerve (V) and falls into three main categories:
- Acute nociceptive: direct stimulation of pulpal or periodontal nociceptors (deep caries, fractures, pericoronitis)
- Inflammatory: release of mediators (prostaglandins, bradykinins, substance P) amplifying pain — pulpitis, acute apical periodontitis
- Neuropathic: rare in routine dentistry; more common post-surgically or in trigeminal neuralgia
The Inflammatory Cascade — Target of Analgesics
NSAIDs act by blocking cyclo-oxygenases (COX), reducing prostaglandin synthesis responsible for nociceptor sensitization:
- Tissue injury → release of arachidonic acid
- COX-1 / COX-2 → prostaglandin synthesis → hyperalgesia
- COX inhibition by NSAIDs → reduced prostaglandins → analgesia + anti-inflammation
Pain Intensity Assessment
| NRS / VAS Score | Level | Recommended Treatment |
|---|---|---|
| 0 – 3 | Mild | Step I — Paracetamol or ibuprofen alone |
| 4 – 6 | Moderate | Reinforced Step I — Paracetamol + NSAID combination |
| 7 – 10 | Severe | Step II — Urgent dental care + multimodal analgesia |
Golden RuleAnalgesics never replace etiological treatment. Dental pain requires a dental procedure — analgesics are bridging therapy or post-operative pain management only.
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Paracetamol — Step I
Mechanism & Pharmacokinetics
Paracetamol acts primarily centrally by inhibiting prostaglandin synthesis in the CNS (COX-3 inhibition). It has no clinically significant peripheral anti-inflammatory effect.
Pharmacokinetics
- Absorption: peak plasma concentration in 30–60 min orally
- Bioavailability: ~80% — Half-life: 2–3 hours
- Hepatic metabolism: at high doses → toxic metabolite NAPQI → hepatotoxicity
- Renal elimination
Adult Dosing
| Form | Unit Dose | Interval | Maximum/Day |
|---|---|---|---|
| Oral tablet | 500 mg – 1 g | Every 6 h | 4 g (3 g if at risk) |
| Effervescent tablet | 500 mg – 1 g | Every 6 h | 4 g |
| Suppository | 500 mg – 1 g | Every 6 h | 4 g |
Reduce to 2–3 g/day in the following cases:
- Body weight < 50 kg — Malnutrition / prolonged fasting
- Mild to moderate hepatic impairment
- Chronic alcoholism — Isoniazid therapy
Availability in Algeria
- Paracetamol Saidal 500 mg / 1 g (tablets)
- Doliprane 500 mg, 1 g — Efferalgan (effervescent) — Panadol 500 mg
- Paediatric: Doliprane syrup, Efferalgan syrup 2.4%
Advantages in Dentistry
- Excellent gastric safety — no gastric protection required
- Safe in pregnancy (all trimesters) — first-choice obstetric analgesic
- Compatible with breastfeeding
- No effect on platelet aggregation — no interference with haemostasis
- Safe for patients on warfarin (AVK)
- Can be combined with NSAIDs or opioids (synergistic effect)
03
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) — Step I
Common Mechanism
NSAIDs inhibit COX-1 and COX-2 cyclo-oxygenases → reduction of prostaglandins → triple effect: analgesic + anti-inflammatory + antipyretic.
COX-1 (constitutive) provides gastric cytoprotection and platelet aggregation. COX-2 (inducible) mediates inflammation. Non-selective NSAIDs inhibit both.
Contraindications Common to All NSAIDsActive peptic ulcer · Renal impairment (GFR < 30 mL/min) · 3rd trimester pregnancy · NSAID/aspirin allergy · Severe heart failure · Severe hepatic cirrhosis · Coagulation disorders (relative)
Ibuprofen — First-Line Reference
Best efficacy/tolerability ratio in its class for acute dental pain. Rapid onset of action: 20–30 min.
| Indication | Dose | Interval | Max/Day |
|---|---|---|---|
| Mild to moderate pain | 200–400 mg | / 6–8 h | 1200 mg |
| Moderate to severe pain | 400–600 mg | / 6–8 h | 2400 mg |
| Post-surgical | 400 mg | / 6 h | 1600–2400 mg |
Products Available in Algeria
- Ibuprofen Saidal 200 mg, 400 mg, 600 mg
- Brufen 200/400/600 mg (tablets, syrup) — Advil — Nurofen
- Paediatric: Advil infant/child syrup 20 mg/mL
Diclofenac
NSAID — mildly COX-2 selective
- SR tablet 75 mg: 1–2 × /day (max 150 mg/day)
- Standard tablet 50 mg: 2–3 × /day
- Topical gel 1%: 3–4 × /day (TMJ)
- Voltaren 50/75 mg, gel 1%
- Diclofenac Saidal 50 mg
- Less favourable cardiovascular profile — prefer ibuprofen first-line
Mefenamic Acid
NSAID — fenamate family
- Loading dose: 500 mg
- Subsequent doses: 250 mg / 6 h
- Maximum duration: 5 days
- Ponstyl / Méfacid / Ponstan 250–500 mg
- Good efficacy for acute pulpal pain
Gastric Protection with NSAIDs
- Treatment < 3 days: not required in patients without risk factors
- Treatment > 5 days or high-risk patient: systematic PPI (omeprazole 20 mg/day in the morning on an empty stomach)
- Risk factors: age > 65, history of ulcer, concurrent corticosteroids, anticoagulants
- Always take ibuprofen/diclofenac with food
Aspirin in DentistryAspirin is not recommended as a routine analgesic: irreversible platelet inhibition (bleeding risk for 7–10 days), less effective than ibuprofen, risk of Reye's syndrome in children. Do not discontinue low-dose antiplatelet aspirin (75–100 mg/day) for routine dental procedures.
04
Opioid Analgesics — Step II
Exceptional and Short-Term Use OnlyOpioid use in dentistry must remain exceptional and limited to a maximum of 3–5 days. Reserved for intense post-surgical pain after Step I failure.
Tramadol
Weak opioid — dual mechanism
- Weak µ-opioid agonist + serotonin/noradrenaline reuptake inhibition
- IR capsule 50 mg: 1 cap / 4–6 h (max 400 mg/day)
- SR tablet 100–200 mg: / 12–24 h
- Tramadol Saidal / Topalgic / Contramal / Algofan drops
- Elderly > 75 years: max 300 mg/day
- Contraindicated < 12 years, uncontrolled epilepsy, MAOIs
Codeine
Weak opioid — morphine prodrug
- Converted to morphine by CYP2D6
- Codoliprane: 1–2 tablets / 4–6 h
- Algisédal (paracetamol 500 mg + codeine 30 mg)
- Always combined with paracetamol
- Contraindicated < 12 years, breastfeeding
Critical Point for Algerian Practice — CodeineThe prevalence of CYP2D6 ultra-rapid metabolisers is higher in North African populations. These patients convert codeine massively into morphine → risk of morphine toxicity even at standard doses. Prefer tramadol over codeine in Algerian practice.
Tramadol Side Effects to Monitor
- Very common (> 10%): nausea, dizziness, drowsiness, headache
- Common: vomiting, constipation, dry mouth, sweating
- Rare but serious: seizures (epileptic patients), serotonin syndrome
- Warn the patient: do not drive, avoid alcohol
- Do not combine with benzodiazepines (major sedation)
05
Detailed Clinical Protocols
Irreversible Pulpitis — Acute Pain
Emergency presentation: intense spontaneous throbbing pain, keeping the patient awake. Definitive treatment: access opening / emergency pulpectomy.
Option 1 — Preferred
- Ibuprofen 400 mg every 6–8 h with meals
- + Paracetamol 1 g every 6 h staggered (1 dose between each NSAID dose)
- Duration: 3–5 days maximum
Option 2 — NSAID Contraindication
- Paracetamol 1 g every 6 h
- + Tramadol 50 mg every 6 h if insufficient
Pregnancy: Paracetamol 1 g / 6 h ONLY (all trimesters). NSAIDs are absolutely contraindicated in the 3rd trimester. Emergency endodontic treatment is safe and recommended even during pregnancy.
Dry Socket (Alveolar Osteitis)
Intense radiating pain at day 3–5 post-extraction, empty/malodorous socket. Local treatment: irrigation + iodoform dressing (Alvogyl).
Systemic Analgesia
- Ibuprofen 400–600 mg / 6 h (with meals) + PPI if > 5 days
- OR Diclofenac 50 mg 2–3 × /day
- OR Ketoprofen 50 mg 2–3 × /day
- If refractory pain: Tramadol 50–100 mg / 6 h as step-up
- Duration: 5–7 days until resolution
Post-Surgical Pain (Complex Extraction, Implant)
Following impacted wisdom tooth extraction, implant placement, or osseous surgery.
Pre-operative — 1 Hour Before the Procedure
- Ibuprofen 400–600 mg (pre-emptive analgesia)
Day 0–3 — Multimodal Analgesia
- Paracetamol 1 g / 6 h
- + Ibuprofen 400 mg / 6–8 h alternating (3 h gap between each)
- Near-continuous 24-hour coverage
Day 3–5 if Pain Persists
- Ibuprofen alone 400 mg / 8 h
- OR Paracetamol alone if NSAIDs insufficient
- If severe: Tramadol 50 mg added (short term only)
Periodontal Abscess / Pericoronitis
Causal treatment: drainage, debridement, irrigation, antibiotics if indicated.
Analgesia — Priority on Anti-Inflammatory Effect
- Ibuprofen 400 mg / 6–8 h (with meals)
- + Paracetamol 1 g / 6 h if needed
- Duration: 3–5 days until infection resolves
Anticoagulated Patient (Warfarin)
Strict Rule
- Paracetamol ONLY 500 mg–1 g / 6 h
- NEVER NSAIDs, aspirin, ketoprofen
- Do not exceed 2 g/day on warfarin
- If insufficient: tramadol 50 mg under monitoring
- Duration: 3–5 days
Renal Impairment
By GFR Level
- GFR 30–60: standard paracetamol / NSAIDs with caution < 3 days
- GFR < 30: paracetamol ONLY
- NSAIDs absolutely contraindicated if GFR < 30
- Tramadol: max 200 mg/day, extended intervals
Paediatric Pain — The 3R Rule
Right dose · Right formulation (age-appropriate) · Right duration (limited)
| Drug | Minimum Age | Dose | Interval |
|---|---|---|---|
| Paracetamol syrup 2.4% | > 1 month | 15 mg/kg/dose | Every 6 h |
| Ibuprofen syrup | > 6 months | 10 mg/kg/dose | Every 6–8 h |
| Tramadol | Contraindicated < 12 years | ||
| Codeine | Contraindicated < 12 years | ||
| Aspirin | Contraindicated < 15 years | ||
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Comparative Drug Overview
| Drug | Anti-inflam. | Gastric | Pregnancy | Anticoag. | Children | Post-extract. |
|---|---|---|---|---|---|---|
| Paracetamol | No | Excellent | All trimesters | Yes | > 1 month | Yes |
| Ibuprofen | Strong | Food required | T1/T2 only | No | > 6 months | Yes |
| Diclofenac | Strong | Food required | T1/T2 only | No | > 14 years | Yes |
| Mefenamic Acid | Moderate | Food required | T1/T2 only | No | > 14 years | Yes |
| Tramadol | No | Good | No | Caution | < 12 years | If needed |
| Codeine | No | Good | Variable | Caution | < 12 years | If needed |
| Aspirin | Moderate | Poor | T3 contraindicated | No | < 15 years | No |
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Clinically Important Drug Interactions
NSAIDs — High-Risk Interactions
| Co-administered Drug | Risk | Management |
|---|---|---|
| Warfarin (AVK) | Increased haemorrhagic risk | Contraindicated — use paracetamol |
| Antiplatelet agents | Potentiated antiplatelet effect | Paracetamol preferred |
| ACE inhibitors / ARBs + diuretics | Triple whammy — acute kidney injury risk | Minimise duration, monitor, ensure hydration |
| Lithium | Lithium toxicity | Contraindicated — use paracetamol instead |
| Methotrexate (> 15 mg/week) | Increased MTX toxicity | Absolute contraindication |
| Corticosteroids | Increased GI risk | Systematic PPI cover |
| Other NSAIDs | No benefit + additive risk | Never combine two NSAIDs |
Tramadol — High-Risk Interactions
| Co-administered Drug | Risk | Management |
|---|---|---|
| MAOIs | Fatal serotonin syndrome | Absolute contraindication — 14-day washout |
| SSRIs (fluoxetine…) | Serotonin syndrome | Avoid combination |
| Benzodiazepines | Severe sedation, respiratory depression | Combination not recommended |
| Alcohol | Potentiated sedation | Prohibited — warn the patient |
| Carbamazepine | Reduced tramadol effect (CYP3A4 induction) | Increase monitoring |
08
Sample Prescriptions
Simple Post-Extraction
Rx 1Paracetamol 1 g
1 tablet / 6 h with meals — 3 days
Ibuprofen 400 mg
1 tablet / 8 h with meals — 3 days
Stagger both drugs by 3 hours
Severe Post-Surgical Pain
Rx 2Paracetamol 1 g
1 tablet / 6 h (with meals) — 5 days
Ibuprofen 400 mg
1 tablet / 6 h (meals, 3 h offset) — 5 days
Omeprazole 20 mg
1 tablet/day, morning fasted — 5 days
NSAID Contraindication
Rx 3Paracetamol 1 g
1 tablet / 6 h — 3–5 days
Tramadol 50 mg
1 capsule / 6–8 h if insufficient — 3–5 days
Do not drive — avoid alcohol
Pregnant Patient (All Trimesters)
Rx 4Paracetamol 1 g
1 tablet / 6 h as needed — 3–5 days
Lowest effective dose for the shortest duration possible
Anticoagulated Patient (Warfarin)
Rx 5Paracetamol 500 mg
1–2 tablets / 6 h — 3–5 days
Do not exceed 2 g/day on warfarin — monitor INR
Child 20 kg (7 years)
Rx 6Paracetamol syrup 2.4%
5 mL (300 mg) / 6 h — 3 days
Ibuprofen syrup 20 mg/mL
4 mL (200 mg) / 8 h — 3 days
Ibuprofen must always be taken with food
09
Clinical FAQ
Studies consistently show that ibuprofen is superior to paracetamol alone for inflammatory dental pain. The ibuprofen + paracetamol combination is the most effective Step I option, due to their complementary mechanisms of action. When NSAIDs are contraindicated (3rd trimester pregnancy, renal impairment, anticoagulation), paracetamol alone remains the first choice.
Yes — it is in fact recommended. A pre-operative dose of ibuprofen 400–600 mg given 1 hour before the procedure significantly reduces post-operative pain (pre-emptive analgesia). This approach prevents nociceptor sensitisation before the painful stimulus, reducing total analgesic consumption in the post-operative period.
No, for routine procedures (simple extraction, standard surgery). The thromboembolic risk from stopping aspirin outweighs the haemorrhagic risk for aspirin ≤ 100 mg/day. Maintain antiplatelet aspirin and manage bleeding locally (compression, sutures, local haemostatic agents). Discontinuation should only be considered for major surgical procedures, in consultation with the cardiologist.
Yes, but only as a last resort (Step II). It is reserved for intense post-surgical pain following osseous surgery (impacted wisdom tooth extraction, implants), or when Step I therapy has failed. Maximum duration is 5 days. It should never be prescribed routinely for common dental pain, which above all requires urgent etiological treatment.
Yes, this is the recommended combination in dentistry. Paracetamol acts primarily centrally (COX-3), while ibuprofen acts peripherally on COX-1 and COX-2. Their synergistic action provides better analgesia without increasing the dose of either drug. The rule is simple: stagger doses by 3 hours to achieve near-continuous 24-hour coverage.
With caution. The prevalence of CYP2D6 ultra-rapid metabolisers is significantly higher in North African populations (1–7% or more). These patients convert codeine massively into morphine, creating a risk of morphine toxicity — profound drowsiness, respiratory depression — even at normal therapeutic doses. Tramadol is preferable in Algerian practice because its efficacy is independent of the CYP2D6 phenotype.
In dentistry, the recommended duration is 5 days maximum for acute pain. Beyond this, mandatory reassessment is required, and gastric protection with a PPI (omeprazole 20 mg/day) is necessary. If pain persists after 5 days, this generally indicates that etiological treatment is incomplete or that a complication needs to be addressed (dry socket, infection, etc.).