Baby Safety / Compounds / Milbemycin oxime

Is Milbemycin oxime safe for babies and kids?

Moderate risk for kids

Infants have immature drug-metabolizing enzymes (CYP450 ontogeny), reduced renal clearance, and different volume of distribution. Accidental exposure or breast milk transfer of Milbemycin oxime poses heightened risk.

What is milbemycin oxime?

The IUPAC name is (1R,4S,5'S,6R,6'R,8R,10E,13R,14E,16E,20R,21Z,24S)-6'-ethyl-24-hydroxy-21-hydroxyimino-5',11,13,22-tetramethylspiro[3,7,19-trioxatetracyclo[15.6.1.14,8.020,24]pentacosa-10,14,16,22-tetraene-6,2'-oxane]-2-one;(1R,4S,5'S,6R,6'R,8R,10E,13R,14E,16E,20R,21Z,24S)-24-hydroxy-21-hydroxyimino-5',6',11,13,22-pentamethylspiro[3,7,19-trioxatetracyclo[15.6.1.14,8.020,24]pentacosa-10,14,16,22-tetraene-6,2'-oxane]-2-one.

Also known as: (1R,4S,5'S,6R,6'R,8R,10E,13R,14E,16E,20R,21Z,24S)-6'-ethyl-24-hydroxy-21-hydroxyimino-5',11,13,22-tetramethylspiro[3,7,19-trioxatetracyclo[15.6.1.14,8.020,24]pentacosa-10,14,16,22-tetraene-6,2'-oxane]-2-one;(1R,4S,5'S,6R,6'R,8R,10E,13R,14E,16E,20R,21Z,24S)-24-hydroxy-21-hydroxyimino-5',6',11,13,22-pentamethylspiro[3,7,19-trioxatetracyclo[15.6.1.14,8.020,24]pentacosa-10,14,16,22-tetraene-6,2'-oxane]-2-one, Interceptor flavor tabs, Milbemite, CGA-179246.

IUPAC name
(1R,4S,5'S,6R,6'R,8R,10E,13R,14E,16E,20R,21Z,24S)-6'-ethyl-24-hydroxy-21-hydroxyimino-5',11,13,22-tetramethylspiro[3,7,19-trioxatetracyclo[15.6.1.14,8.020,24]pentacosa-10,14,16,22-tetraene-6,2'-oxane]-2-one;(1R,4S,5'S,6R,6'R,8R,10E,13R,14E,16E,20R,21Z,24S)-24-hydroxy-21-hydroxyimino-5',6',11,13,22-pentamethylspiro[3,7,19-trioxatetracyclo[15.6.1.14,8.020,24]pentacosa-10,14,16,22-tetraene-6,2'-oxane]-2-one
CAS number
129496-10-2
Molecular formula
C63H88N2O14
Molecular weight
1097.4 g/mol
SMILES
CCC1C(CCC2(O1)CC3CC(O2)CC=C(CC(C=CC=C4COC5C4(C(C=C(C5=NO)C)C(=O)O3)O)C)C)C.CC1CCC2(CC3CC(O2)CC=C(CC(C=CC=C4COC5C4(C(C=C(C5=NO)C)C(=O)O3)O)C)C)OC1C
PubChem CID
20056431

Risk for babies

Moderate risk

Infants have immature drug-metabolizing enzymes (CYP450 ontogeny), reduced renal clearance, and different volume of distribution. Accidental exposure or breast milk transfer of Milbemycin oxime poses heightened risk.

Neonates and infants up to 12 months have incomplete blood-brain barrier development, immature Phase I/II metabolic enzymes (particularly CYP3A4, UGT1A1), and higher gastrointestinal permeability. Equivalent doses produce higher internal concentrations and longer residence times.

What to do: Minimize infant exposure through source control. For breastfeeding mothers: reduce maternal exposure. For formula-fed infants: use certified low-migration bottles and verified water sources. Consult pediatrician regarding any concerns.

Risk for pregnant and nursing people

Elevated risk

Milbemycin oxime poses pregnancy risk through potential teratogenicity, altered pharmacokinetics (increased blood volume, changed CYP activity), and placental transfer. FDA pregnancy category should be evaluated.

Suspected reproductive toxicant (GHS H361) or suspected endocrine disruptor. Precautionary approach warranted. Animal studies or limited human data suggest developmental toxicity potential.

What to do: Minimize exposure during pregnancy and lactation. Consult healthcare provider regarding specific risks. Consider alternative products with lower hazard profiles.

Regulatory consensus

1 regulatory bodyhas classified Milbemycin oxime.

AgencyYearClassificationNotes
IARC2023Not evaluated by IARC — milbemycin oxime is an FDA/CVM-approved veterinary macrolide antiparasitic (dogs, cats) for heartworm prevention, mite treatment, and intestinal parasite control; no carcinogenicity classification; primary safety concern is neurotoxicity in MDR1 (ABCB1)-deficient dog breeds (Collies, Shetland Sheepdogs, Australian Shepherds and related breeds with P-glycoprotein deficiency)

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where kids encounter milbemycin oxime

  • Industrial FacilitiesManufacturing plants, Chemical storage areas, Waste treatment sites
  • Occupational EnvironmentsFactories, Warehouses, Transportation vehicles

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Milbemycin oxime:

  • Alternative drug class; Non-pharmacological therapy; Lowest effective dose
    Trade-offs: Direct chemical substitution requires verification that the replacement does not introduce new hazards (regrettable substitution). Conduct full hazard assessment of proposed alternative before adoption.
    Relative cost: 1.2-2×

Frequently asked questions

Is milbemycin oxime safe for kids?

Infants have immature drug-metabolizing enzymes (CYP450 ontogeny), reduced renal clearance, and different volume of distribution. Accidental exposure or breast milk transfer of Milbemycin oxime poses heightened risk.

What products contain milbemycin oxime?

Milbemycin oxime appears in: Manufacturing plants (Industrial facilities); Chemical storage areas (Industrial facilities); Factories (Occupational environments); Warehouses (Occupational environments).

What should I do if my child is exposed to milbemycin oxime?

Minimize infant exposure through source control. For breastfeeding mothers: reduce maternal exposure. For formula-fed infants: use certified low-migration bottles and verified water sources. Consult pediatrician regarding any concerns.

See Milbemycin oxime in the baby app

Look up products containing milbemycin oxime, compare to alternatives, and explore the full data record.

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Sources (1)

  1. Milbemycin Oxime FDA CVM Interceptor Sentinel Trifexis; Streptomyces hygroscopicus Macrolide Milbemycin A3 A4 Oxime; GluCl GABA-Gated Chloride Channel Invertebrate; MDR1 ABCB1 P-Glycoprotein Collie Herding Breed Neurotoxicity; Dirofilaria Heartworm Prevention; Demodex Sarcoptes Mange; WSU MDR1 Genetic Testing; Log Kow Aquatic Invertebrate Ecotoxicity; IARC Not Evaluated (2023) — regulatory

Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →