Pure opioid agonists

Question 1

Hydrocodone

Answer 1

• AKA Tussigon
• Pure opioid (Mu) agonist
• Oral form of hydromorphone
• Dogs: 1-2 mg/kg PO
• Reversal agent: Naloxone 0.04 mg/kg
• Adverse effects: respiratory depression in high doses
• Contraindications/ Cautions: hypersensitivity to narcotic analgesics, DO NOT USE COMBINATION PRODUCTS CONTAINING ACETAMINOPHINE IN CATS
• Drug interactions: Acepromazine, phenobarbital, anticholinergics, MOA inhibitors, CNS depressants

Question 2

Hydromorphone

Answer 2

• AKA Dilaudid
• 2 mg/ml, 10 mg/ml
• Pure opioid (Mu) agonist
• Excellent analgesic properties
• IV, IM, SQ administration
• Dogs and cats: 0.1 - 0.2 mg/kg q4h
• Reversal agent: Naloxone 0.04 mg/kg
• Adverse effects: nausea/ vomiting, panting
• Contraindications/ Cautions: Hypersensitivity to narcotic analgesics, diarrhea caused by toxic ingestion

Question 3

Fentanyl (Injectable)

Answer 3

• Pure opioid (Mu) agonist
• 50 mcg/ml
• Excellent analgesic properties
• IV administration, can give IM but very short acting
• Dogs and cats: 2-10 mcg/kg
• Recommended initial loading dose 5 mcg/kg
• Reversal agent: Naloxone 0.04 mg/kg
• Very short acting (15-30 min)
• Ideal use as an opioid CRI
• Can be used as an adjunct induction agent is septic patients 10 mcg/kg
• Adverse effects: respiratory depression, CNS depression, and bradycardia
• Contraindications/ Cautions: Known hypersensitivity to the drug or its components

Question 4

Fentanyl Transdermal Patches

Answer 4

• Pure opioid (Mu) agonist
• Variable analgesic- largely depends on application and contact with skin
• Dermal patch
• Dogs and cats: 2-4 mcg/kg/hr
• Reversal agent: Naloxone 0.04 mg/kg
• Patch sizes: 12 mcg/hr, 25 mcg/hr, 50 mcg/hr, 75 mcg/hr, 100 mcg/hr
• Approved locations: thorax, metatarsal, base of tail- Patients MUST wear E-collars
• WEAR GLOVES WHEN APPLYING/ REMOVING/ RE- WRAPPING
• Adverse effects: rash at patch site, urine retention and constipation, pyrexia
• Contraindications/ Cautions: do not place on exposed heat sources (heating pads, warm water blankets, etc- can be fatal as it causes increased drug release and absorption time), DO NOT TRIM PATCHES – use closest appropriate size

Question 5

Methadone

Answer 5

• Pure opioid (Mu) agonist
• 10 mg/ml
• Excellent analgesic properties
• IV, IM, SQ administration
• Dogs and cats: 0.2 - 0.5 mg/kg q4h
• Recommended starting dose: 0.3 mg/kg
• Reversal agent: Naloxone 0.04 mg/kg
• Adverse effects: respiratory depression
• Contraindications/ Cautions: Hypersensitivity to narcotic analgesics

Question 6

Morphine

Answer 6

• Pure opioid (Mu) agonist
• 1 mg/ml (preservative free), 10 mg/ml, 15 mg/ml
• Excellent analgesic properties
• IM administration (recommend to use maropitant premed to reduce chances of vomiting)
• IV administration can cause histamine reaction, only use IV in CRI
• Dogs and cats: 0.05-0.5 mg/kg IM
• Recommended starting dose: 0.1 mg/kg
• Reversal agent: Naloxone 0.04 mg/kg
• Adverse effects: respiratory depression, nausea/vomiting
• Contraindications/ Cautions: IV bolus use, diarrhea caused by toxic ingestion

Question 7

Sufentanil

Answer 7

• Pure opioid (Mu) agonist
• 50 mcg/ml
• Excellent analgesic properties
• IV administration, can give IM but very short acting
• Dogs and cats:
• Recommended initial loading dose
• Reversal agent: Naloxone 0.04 mg/kg
• Very short acting (30 min?)
• Ideal use as an opioid CRI
• Adverse effects: respiratory depression
• Contraindications/Cautions: EXTREMELY POTENT, HIGHLY CONCENTRATED 5 times more potent than Fentanyl, may cause respiratory arrest if dosed incorrectly