Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ACTIQ vs BACTRIM PEDIATRIC
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Opioid agonist; binds to mu-opioid receptors in the CNS, altering pain perception and response.
Bactrim (sulfamethoxazole/trimethoprim) is a combination of two antifolate agents. Sulfamethoxazole inhibits dihydropteroate synthase, blocking the conversion of PABA to dihydrofolic acid. Trimethoprim inhibits dihydrofolate reductase, preventing the reduction of dihydrofolic acid to tetrahydrofolic acid. Sequential blockade of folate synthesis leads to bacteriostasis.
Management of breakthrough pain in cancer patients aged 16 and older who are already receiving and tolerant to opioid therapy for their underlying persistent cancer pain
Urinary tract infections due to susceptible strains of E. coli, Klebsiella, Enterobacter, Morganella, Proteus, and Providencia,Acute otitis media in children,Acute exacerbations of chronic bronchitis in adults,Shigellosis,Pneumocystis jirovecii pneumonia (PCP) prophylaxis and treatment,Traveler's diarrhea (FDA-approved),Toxoplasmosis (off-label),Nocardiosis (off-label),Chancroid (off-label),Brucellosis (off-label)
200 mcg transmucosally, titrated upward as needed; initial dose for opioid-tolerant patients is 200 mcg, with additional doses possible after 15 minutes if needed. Maximum 4 doses per episode. At least 4 hours between episodes.
Oral: 160 mg trimethoprim / 800 mg sulfamethoxazole (one DS tablet) every 12 hours for 14 days. For Pneumocystis jirovecii pneumonia: 15-20 mg/kg/day of trimethoprim component divided every 6-8 hours.
Terminal half-life 0.83–2 hours (mean 1.3 h) in adults; note that context: transmucosal absorption leads to rapid onset but short duration; half-life is not correlated with clinical effect due to oral transmucosal route and rapid redistribution.
Sulfamethoxazole: 9-12 hours (prolonged in renal impairment; up to 30 hours with Cr Cl <30 m L/min). Trimethoprim: 8-10 hours (prolonged to 20-30 hours in severe renal impairment).
Primarily hepatic via CYP3A4 to inactive metabolites (norfentanyl, despropionylfentanyl, hydroxyfentanyl) and other metabolites; <7% excreted unchanged in urine.
Sulfamethoxazole is metabolized via acetylation and glucuronidation; trimethoprim is metabolized via oxidation (demethylation) and conjugation. CYP450 enzymes have minor involvement.
Primarily renal as metabolites (about 75% as metabolites, <10% unchanged). Fecal excretion accounts for <9%. Biliary excretion is minor.
Renal: sulfamethoxazole 85% (30% unchanged, rest as acetylated and glucuronide conjugates), trimethoprim 60-80% (10-30% unchanged). Fecal/biliary: <4%.
Fentanyl is 80–85% bound to plasma proteins (primarily albumin and α1-acid glycoprotein).
Sulfamethoxazole: 70% bound to albumin. Trimethoprim: 42-46% bound to albumin and alpha-1-acid glycoprotein.
Approximately 4 L/kg (range 3–6 L/kg); large Vd indicates extensive tissue distribution and redistribution contributing to short duration.
Sulfamethoxazole: 0.15-0.3 L/kg. Trimethoprim: 1.3-2.0 L/kg indicating extensive tissue distribution.
Oral transmucosal: 50% (range 47–54%) relative to IV; variable and enhanced by rapid absorption through buccal mucosa.
Oral: sulfamethoxazole 100%; trimethoprim 100% (both well absorbed).
No specific GFR-based dose adjustment recommended; use with caution in severe renal impairment (Cr Cl < 30 m L/min) and consider dose reduction due to potential accumulation.
Cr Cl >30 m L/min: No adjustment. Cr Cl 15-30 m L/min: Reduce dose by 50% (e.g., one DS tablet every 24 hours). Cr Cl <15 m L/min: Contraindicated (unless with hemodialysis). For PJP: Cr Cl 15-29 m L/min: 15-20 mg/kg/day (trimethoprim) divided every 8 hours; Cr Cl <15 m L/min: Not recommended.
Child-Pugh Class A/B: No adjustment. Child-Pugh Class C: Reduce initial dose to 100 mcg and titrate slowly; monitor closely for prolonged effects.
Child-Pugh Class A: No adjustment. Child-Pugh Class B: Caution; consider reducing dose or monitoring liver function. Child-Pugh Class C: Avoid use due to potential hepatotoxicity and altered metabolism.
Not approved for pediatric use; safety and efficacy not established in patients under 16 years.
Trimethoprim component dosing: 8 mg/kg/day divided every 12 hours for urinary tract infection or otitis media. For Pneumocystis jirovecii pneumonia (PJP) prophylaxis: 150 mg/m2/day of trimethoprim divided every 12 hours, given 3 times per week. For PJP treatment: 15-20 mg/kg/day of trimethoprim divided every 6-8 hours. Maximum daily dose: 960 mg trimethoprim.
Initiate at 100 mcg transmucosally; titrate slowly due to increased sensitivity and risk of respiratory depression. Monitor for adverse effects.
Monitor renal function and adjust dose based on Cr Cl. Increased risk of hyperkalemia, hematologic toxicity, and adverse reactions. Consider starting at lower end of dosing range. Avoid in patients with Cr Cl <15 m L/min.
Risk of respiratory depression, addiction, abuse, and misuse; accidental ingestion can be fatal; concomitant use with benzodiazepines or CNS depressants may cause profound sedation, respiratory depression, coma, and death; not for use in opioid non-tolerant patients; risk of neonatal opioid withdrawal syndrome with prolonged use during pregnancy; serious, life-threatening, or fatal respiratory depression may occur even at recommended doses.
Fatalities associated with sulfonamide hypersensitivity reactions including Stevens-Johnson syndrome, toxic epidermal necrolysis, fulminant hepatic necrosis, agranulocytosis, aplastic anemia, and other blood dyscrasias have been reported. Use in pregnant women at term and in nursing mothers may cause kernicterus.
Risk of respiratory depression; addiction, abuse, and misuse; interactions with CNS depressants; serotonin syndrome; adrenal insufficiency; severe hypotension; seizures; withdrawal; use in patients with head injuries, increased intracranial pressure, biliary tract disease, pancreatitis; risk of choking with lozenge; oral mucosal irritation; dental caries; hypokalemia; hyponatremia; use in elderly, cachectic, or debilitated patients.
Monitor for hypersensitivity reactions, blood dyscrasias, and hepatic injury. Caution in elderly, folate deficiency, impaired renal/hepatic function, G6PD deficiency, and severe allergies or bronchial asthma. Avoid in infants <2 months of age. Use with caution in patients with porphyria or thyroid dysfunction.
Significant respiratory depression; acute or severe bronchial asthma in an unmonitored setting or without resuscitative equipment; known or suspected paralytic ileus; hypersensitivity to fentanyl or any component; opioid non-tolerant patients; management of acute or postoperative pain including headache/migraine, dental pain, or emergency department use.
Hypersensitivity to any component (sulfonamides, trimethoprim), severe liver damage, marked renal impairment (Cr Cl <15 ml/min), megaloblastic anemia due to folate deficiency, pregnancy at term, nursing mothers, infants <2 months of age.
No significant food interactions. Grapefruit juice may increase fentanyl levels, but specific studies with ACTIQ are lacking. Avoid alcohol, as it may increase sedation and respiratory depression risk.
Avoid high-potassium foods if at risk for hyperkalemia (e.g., bananas, oranges, salt substitutes). May reduce folic acid levels; encourage folate-rich foods (leafy greens, legumes). Take with food if GI upset occurs. Avoid alcohol due to disulfiram-like reaction.
FDA Pregnancy Category C. First trimester: limited human data; animal studies show increased resorptions and fetal growth restriction. Second/third trimester: chronic use may cause neonatal opioid withdrawal syndrome; avoid use during labor due to risk of neonatal respiratory depression.
First trimester: associated with increased risk of neural tube defects, cardiovascular malformations, and urinary tract anomalies due to folate antagonism (trimethoprim). Second and third trimesters: risk of kernicterus in the newborn due to sulfamethoxazole displacing bilirubin from albumin. Avoid during pregnancy, especially in the first and third trimesters.
Excreted in breast milk; M/P ratio not established. Limited data suggest low levels, but risk of infant sedation and respiratory depression. Avoid use while breastfeeding unless potential benefit outweighs risk.
Both components are excreted in breast milk. M/P ratio for sulfamethoxazole is approximately 0.3; for trimethoprim, approximately 1.1. Caution in infants with G6PD deficiency, hyperbilirubinemia, or jaundice. Consider alternatives, especially in preterm or sick infants.
Due to increased plasma volume and hepatic metabolism in pregnancy, dose requirements may increase; adjust based on clinical response and tolerance. Avoid use during labor and delivery due to risk of neonatal respiratory depression; short-term use preferred.
Dose adjustments are not specifically recommended for pregnancy, but use with caution. Monitor serum drug levels if prolonged therapy. Avoid sulfamethoxazole near term due to risk of kernicterus. Ensure adequate folic acid supplementation (5 mg daily) to mitigate folate antagonism.
ACTIQ is a transmucosal immediate-release fentanyl formulation indicated for breakthrough cancer pain in opioid-tolerant patients. Initiate with the lowest strength (200 mcg) and titrate upward. Avoid use in opioid-naive patients due to risk of fatal respiratory depression. Place the unit between cheek and lower gum, not sublingually. Instruct patient not to bite or suck the unit. Monitor for sedation and respiratory depression. Multiple units may be used per episode if needed, but wait at least 4 hours before next episode. Dispose of partially used units by flushing down toilet.
Bactrim Pediatric (sulfamethoxazole/trimethoprim) is contraindicated in infants <2 months due to risk of kernicterus. Monitor for hyperkalemia, especially in elderly or renal impairment. Use with caution in folate deficiency; supplement folinic acid if prolonged therapy. Avoid in G6PD deficiency due to hemolytic anemia risk.
Only use ACTIQ if you are already taking regular around-the-clock opioid pain medicine and are tolerant to opioids.,Do not use ACTIQ for short-term pain like after surgery, headache, or dental pain.,Place the unit in your cheek pouch, not under your tongue. Do not chew or suck it.,If you need more than 4 units per day, contact your doctor as your dose may need adjustment.,Store ACTIQ in a safe place away from children, as accidental ingestion can be fatal.,Dispose of unused or partially used units by flushing them down the toilet.
Take with a full glass of water to prevent crystalluria.,Complete full course even if symptoms improve.,Avoid prolonged sun exposure; use sunscreen.,Report rash, fever, sore throat, or bruising immediately.,Do not use if allergic to sulfa drugs or thiazide diuretics.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about ACTIQ vs BACTRIM PEDIATRIC, answered by our medical review team.
ACTIQ is a Opioid Analgesic that works by Opioid agonist; binds to mu-opioid receptors in the CNS, altering pain perception and response.. BACTRIM PEDIATRIC is a Sulfonamide Antibiotic Combination that works by Bactrim (sulfamethoxazole/trimethoprim) is a combination of two antifolate agents. Sulfamethoxazole inhibits dihydropteroate synthase, blocking the conversion of PABA to dihydrofolic acid. Trimethoprim inhibits dihydrofolate reductase, preventing the reduction of dihydrofolic acid to tetrahydrofolic acid. Sequential blockade of folate synthesis leads to bacteriostasis.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ACTIQ and BACTRIM PEDIATRIC depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of ACTIQ is: 200 mcg transmucosally, titrated upward as needed; initial dose for opioid-tolerant patients is 200 mcg, with additional doses possible after 15 minutes if needed. Maximum 4 doses per episode. At least 4 hours between episodes.. The standard adult dose of BACTRIM PEDIATRIC is: Oral: 160 mg trimethoprim / 800 mg sulfamethoxazole (one DS tablet) every 12 hours for 14 days. For Pneumocystis jirovecii pneumonia: 15-20 mg/kg/day of trimethoprim component divided every 6-8 hours.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between ACTIQ and BACTRIM PEDIATRIC in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. ACTIQ is classified as Category C. FDA Pregnancy Category C. First trimester: limited human data; animal studies show increased resorptions and fetal growth restriction. Second/third trimester: chronic use may cause. BACTRIM PEDIATRIC is classified as Category C. First trimester: associated with increased risk of neural tube defects, cardiovascular malformations, and urinary tract anomalies due to folate antagonism (trimethoprim). Second an. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.