Pronunciation (a seet a MIN oh fen, KAF een, & dye hye droe KOE deen)

U.S. Brand Names Panlor DC; Panlor SS

Synonyms Caffeine, Dihydrocodeine, and Acetaminophen; Dihydrocodeine Bitartrate, Acetaminophen, and Caffeine

Therapeutic Category
Analgesic Combination (Narcotic)
Use Relief of moderate to moderately-severe pain

Restrictions C-III

Pregnancy Risk Factor C

Pregnancy Implications Reproduction studies have not been conducted with this combination.

Contraindications Hypersensitivity to acetaminophen, caffeine, dihydrocodeine, codeine, or any component of the formulation; significant respiratory depression (in unmonitored settings); acute or severe bronchial asthma; hypercapnia; paralytic ileus

Warnings/Precautions Acetaminophen may cause severe hepatotoxicity in acute overdose; in addition, chronic daily dosing in adults of 5-8 g of acetaminophen over several weeks or 3-4 g/day of acetaminophen for one year have resulted in liver damage. Use with caution in patients with alcoholic liver disease; consuming 3 alcoholic drinks/day may increase the risk of liver damage. Use caution in patients with known G6PD deficiency. Caffeine may cause CNS and cardiovascular stimulation as well as GI irritation in high doses. Dihydrocodeine should be used with caution in patients with hypersensitivity reactions to other phenanthrene derivative opioid agonists (morphine, hydrocodone, hydromorphone, levorphanol, oxycodone, oxymorphone), respiratory diseases including asthma, emphysema, COPD, or severe hepatic or renal insufficiency. Use caution with MAO inhibitors.
This combination should be used with caution in elderly or debilitated patients, hypotension, adrenocortical insufficiency, thyroid disorders, prostatic hyperplasia, urethral stricture, seizure disorder, CNS depression, head injury or increased intracranial pressure. Causes sedation; caution must be used in performing tasks which require alertness (eg, operating machinery or driving). Safety and efficacy in pediatric patients have not been established.

Adverse Reactions Frequency not defined. Most common reactions with this combination include:

Central nervous system: Dizziness, drowsiness, lightheadedness, sedation

Dermatologic: Pruritus, skin reactions

Gastrointestinal: Constipation, nausea, vomiting

Drug Interactions

Acetaminophen: Substrate (minor) of CYP1A2, 2A6, 2C8/9, 2D6, 2E1, 3A4; Inhibits CYP3A4 (weak)

Caffeine: Substrate of CYP1A2 (major), 2C8/9 (minor), 2D6 (minor), 2E1 (minor), 3A4 (minor); Inhibits CYP1A2 (weak), 3A4 (moderate)

Dihydrocodeine: Substrate of CYP2D6 (major)

Acetaminophen: See individual monograph for associated interactions.

Caffeine:

CYP1A2 inhibitors: CYP1A2 inhibitors may increase the levels/effects of caffeine. Example inhibitors include amiodarone, fluvoxamine, ketoconazole, quinolone antibiotics, and rofecoxib.

CYP3A4 substrates: Caffeine may increase the levels/effects of CYP3A4 substrates. Example substrates include benzodiazepines, calcium channel blockers, ergot derivatives, mirtazapine, nateglinide, nefazodone, tacrolimus, and venlafaxine.

Quinolone antibiotics: Quinolones may increase the level/effects of caffeine.

Dihydrocodeine:

CYP2D6 inhibitors: CYP2D6 inhibitors may decrease the effects of dihydrocodeine. Example inhibitors include chlorpromazine, delavirdine, fluoxetine, miconazole, paroxetine, pergolide, quinidine, quinine, ritonavir, and ropinirole.

Quinidine: Quinidine may decrease the effects of dihydrocodeine.

Food Interactions

Ethanol: Excessive intake of ethanol may increase the risk of acetaminophen-induced toxicity. Ethanol may also increase CNS depression.

Mechanism of Action

Acetaminophen inhibits the synthesis of prostaglandins in the central nervous system and peripherally blocks pain impulse generation; produces antipyresis from inhibition of hypothalamic heat-regulating center.

Caffeine is a CNS stimulant; use with acetaminophen and dihydrocodeine increases the level of analgesia provided by each agent.

Dihydrocodeine binds to opiate receptors in the CNS, causing inhibition of ascending pain pathways, altering the perception of and response to pain; produces generalized CNS depression.

Usual Dosage Oral: Adults: Relief of pain:

Panlor DC: 2 capsules every 4 hours as needed; adjust dose based on severity of pain (maximum dose: 10 capsules/24 hours)

Panlor SS: 1 tablet every 4 hours as needed; adjust dose based on severity of pain (maximum dose: 5 tablets/24 hours)

Dosage Forms

Capsule (Panlor DC): Acetaminophen 356.4 mg, caffeine 30 mg, and dihydrocodeine bitartrate 16 mg

Tablet (Panlor SS): Acetaminophen 712.8 mg, caffeine 60 mg, and dihydrocodeine bitartrate 32 mg