codeine phosphate (redirected from Opioid Agonist)

codeine phosphate,

an opioid analgesic and antitussive.

indications It is prescribed to suppress cough and to relieve mild to moderate pain.

contraindication Known hypersensitivity to opiates is the only contraindication.

adverse effects Among the more serious adverse reactions are depression of the central nervous system, paradoxic excitement, and drug dependence.

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codeine phosphate Warning - High-alert drug!

Pharmacologic class: Opioid agonist

Therapeutic class: Opioid analgesic, antitussive

Controlled substance schedule II

Pregnancy risk category C

Action

Binds to opioid receptors in CNS, altering perception of painful stimuli. Causes generalized CNS depression, decreases cough reflex, and reduces GI motility.

Availability

Injection (phosphate): 30 mg/ml, 60 mg/ml

Oral solution (phosphate): 10 mg/5 ml, 15 mg/5 ml

Tablets (sulfate): 15 mg, 30 mg, 60 mg; 30 mg, 60 mg (soluble)

⊘Indications and dosages

➣ Pain

Adults: 15 to 60 mg P.O. or 15 to 60 mg (phosphate) I.M., I.V., or subcutaneously q 4 to 6 hours. Usual daily dosage is 30 mg; maximum daily dosage is 360 mg.

Children ages 1 and older: 0.5 mg/kg or 15 mg/m² P.O., I.M., or subcutaneously q 4 to 6 hours

➣ Cough

Adults: 10 to 20 mg P.O. q 4 to 6 hours as needed. Don't exceed 120 mg/day.

Children ages 6 to 12: 5 to 10 mg P.O. q 4 to 6 hours as needed. Don't exceed 60 mg/day.

Children ages 2 to 6: 2.5 to 5 mg P.O. q 4 to 6 hours as needed. Don't exceed 30 mg/day.

Dosage adjustment

• Elderly or debilitated patients

Contraindications

• Hypersensitivity to narcotics
• Labor and delivery of premature neonate
• Premature neonates

Precautions

Use cautiously in:
• severe renal, hepatic, or pulmonary disease
• adrenal insufficiency, head trauma, hypothyroidism, increased intracranial pressure, prostatic hypertrophy, undiagnosed abdominal pain, alcoholism
• elderly patients
• pregnant or breastfeeding patients.

Administration

• If GI upset occurs, give with food.
• Titrate dosage for appropriate analgesic effect.
• When changing administration route, be aware that oral dose is two-thirds as effective as parenteral dose.
☞ Don't give I.V. to children.
☞ If overdose occurs, give naloxone I.V. as prescribed. Repeat administration as needed (up to manufacturer's recommended maximum dosage) to reverse toxic effects.
☞ Don't mix with other solutions; drug is incompatible with other drugs.

Route	Onset	Peak	Duration
P.O.	30-45 min	1-2 hr	4 hr
I.M.	10-30 min	30-60 min	4 hr
Subcut.	10-30 min	Unknown	4 hr

Adverse reactions

CNS: confusion, sedation, malaise, agitation, euphoria, floating feeling, headache, hallucinations, unusual dreams, apathy, mood changes

CV: hypotension, bradycardia, peripheral vasodilation, reduced peripheral resistance

EENT: blurred or double vision, miosis, reddened sclera

GI: nausea, vomiting, constipation, decreased gastric motility

GU: urinary retention, urinary tract spasms, urinary urgency

Respiratory: suppressed cough reflex, respiratory depression

Skin: flushing, sweating

Other: physical or psychological drug dependence, drug tolerance

Interactions

Drug-drug. Antidepressants, antihistamines, sedative-hypnotics: additive CNS depression

Nalbuphine, pentazocine: decreased analgesic effect

Opioid partial agonists (buprenorphine, butorphanol, nalbuphine, pentazocine): precipitation of opioid withdrawal in physically dependent patients

Drug-herbs. Chamomile, hops, kava, skullcap, valerian: increased CNS depression

Drug-behaviors. Alcohol use: increased CNS depression

Patient monitoring

• Monitor vital signs and CNS status.
• Assess pain level and efficacy of pain relief.
• Evaluate patient for adverse reactions.
☞ Stay alert for overdose signs and symptoms, such as CNS and respiratory depression, GI cramping, and constipation.
• Assess other drugs in patient's drug regimen for those that could cause additive or adverse interactions.
• Monitor patient for signs and symptoms of drug dependence or tolerance.

Patient teaching

• With oral use, advise patient to minimize adverse GI effects by taking doses with food or milk.
☞ Tell patient to notify prescriber promptly if he experiences shortness of breath or difficulty breathing or if nausea, vomiting, or constipation become pronounced.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration, alertness, vision, coordination, and physical dexterity.
• Instruct patient to move slowly when sitting up or standing, to avoid dizziness or light-headedness from sudden blood pressure decrease.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, herbs, and behaviors mentioned above.