피리메타민
Pyrimethamine
Aminopyrimidine derivative
다른 이름: Daraprim · Malocide · Pirimecidan · BW-50-63 · pirimetamina · pyrimethaminum · RP-4753
VetSheet 수의사 팀 검수업데이트 2026년 4월 5일근거 기반 수의학 참고자료
용량은 수의사 전문가를 위한 임상 참고자료입니다. 반드시 최신 약물 정보 및 개별 환자에 따라 확인하시기 바랍니다.
동물 종별 용량
🌎 NA — North America🌍 EU — Europe
개
| 적응증 | 용량 | 경로 | 빈도 | 기간 | 지역 |
|---|---|---|---|---|---|
| Toxoplasmosis | 0.5-1 mg/kg PO once daily for 2 days, then 0.25 mg/kg PO once daily for 2 weeks | PO | once daily | 2 days, then 2 weeks | 🌎 NA |
| Toxoplasmosis | 0.25-0.5 mg/kg once daily for 28 days | PO | once daily | 28 days | 🌎 NA |
| Neospora | 1 mg/kg once daily for 28 days | PO | once daily | 28 days | 🌎 NA |
| Hepatazoon canis | 0.25-0.5 mg/kg once daily for 2-4 weeks | PO | once daily | 2-4 weeks | 🌎 NA |
| Hepatazoon americanum | 0.25 mg/kg PO q24h | PO | q24h | — | 🌎 NA |
| Hepatazoon americanum | 0.25 mg/kg PO q24h for 14 days | PO | q24h | 14 days | 🌎 NA |
| Neosporosis | 1 mg/kg PO daily | PO | daily | — | 🌎 NA |
- Toxoplasmosis: Given with sulfadiazine at 30-50 mg/kg PO divided two to four times a day for 1-2 weeks
- Neospora: Given with trimethoprim sulfa
- Hepatazoon canis: Given with trimethoprim sulfa and clindamycin
- Hepatazoon americanum: Given with Trimethoprim/sulfa (15 mg/kg PO q12h) and clindamycin (10 mg/kg q8h). Once remission attained, decoquinate can maintain.
- Hepatazoon americanum: Given with Trimethoprim/sulfa (15 mg/kg PO q12h for 14 days) and clindamycin (10 mg/kg q8h for 14 days). Once remission attained, decoquinate can maintain.
- Neosporosis: Given with trimethoprim/sulfa (15-30 mg/kg PO twice daily).
고양이
| 적응증 | 용량 | 경로 | 빈도 | 기간 | 지역 |
|---|---|---|---|---|---|
| Toxoplasmosis | 0.5-1 mg/kg PO once daily for 2 days, then 0.25 mg/kg PO once daily for 2 weeks | PO | once daily | 2 days, then 2 weeks | 🌎 NA |
| Toxoplasmosis (enteroepithelial cycle) | 2 mg/kg, PO once daily | PO | once daily | — | 🌎 NA |
| Toxoplasmosis (extraintestinal cycle) | 0.5-1 mg/kg PO divided two to three times daily | PO | divided two to three times daily | — | 🌎 NA |
| Protozoal myocarditis | 1 mg/kg PO once daily for 3 days, then decrease dose to 0.5 mg/kg PO once a day | PO | once daily | 3 days, then ongoing | 🌎 NA |
| Toxoplasmosis | 0.5 mg/kg PO per day | PO | per day | 7-10 days | 🌎 NA |
- Toxoplasmosis: Given with sulfadiazine at 30-50 mg/kg PO divided two to four times a day for 1-2 weeks
- Toxoplasmosis (extraintestinal cycle): Combined with sulfonamides (e.g., triple sulfa, sulfadiazine) at 60 mg/kg PO or IM divided two to three times daily
- Protozoal myocarditis: Given with sulfadimethoxine 25 mg/kg PO, IV, or IM once a day
- Toxoplasmosis: Given with sulfadiazine at 30 mg/kg, PO q12h. Do not use continuously for longer than 2 weeks. Supplementation with folic acid 5 mg/day or folinic acid 1 mg/kg/day may alleviate toxicity.
새
| 적응증 | 용량 | 경로 | 빈도 | 기간 | 지역 |
|---|---|---|---|---|---|
| Coccidian organisms in raptors (Toxoplasmosis, Atoxoplasmosis, Sarcocystis) | 0.5 mg/kg PO twice daily for 14-28 days | PO | twice daily | 14-28 days | 🌎 NA |
말
| 적응증 | 용량 | 경로 | 빈도 | 기간 | 지역 |
|---|---|---|---|---|---|
| Equine protozoal myeloencephalitis | 1 mg/kg PO once a day for 90-120 days (or longer) | PO | once a day | 90-120 days (or longer) | 🌎 NA |
- Equine protozoal myeloencephalitis: Given with a sulfa or potentiated sulfa (sulfadiazine 20 mg/kg PO once or twice a day). Monitor CBC's.
용량은 수의사 전문가를 위한 임상 참고자료입니다. 반드시 최신 약물 정보 및 개별 환자에 따라 확인하시기 바랍니다.
개요
피리메타민은 강력한 항원충제로, 수의학에서는 주로 소동물의 톡소플라스마증, 네오스포라증, Hepatozoon americanum과 같은 중증 원충 감염 및 말의 말 원충성 척수뇌염(EPM) 치료에 사용됩니다. 엽산 합성을 상승적으로 차단하기 위해 거의 항상 설파계 항생제와 병용 투여됩니다.
임상 요점: 엽산 대사를 표적으로 하기 때문에, 특히 고양이에서 숙주의 골수 억제가 심각한 위험이 될 수 있습니다. 혈액학적 독성을 완화하기 위해 폴리닌산(원충이 이용할 수 있는 엽산이 아님)이나 제빵용 효모의 보충이 종종 권장됩니다.
작용 기전
Pyrimethamine is a folic acid antagonist. It competitively inhibits the enzyme dihydrofolate reductase (DHFR) → blocks the reduction of dihydrofolic acid to tetrahydrofolic acid (the active form of folate) → depletes folate reserves essential for purine and pyrimidine synthesis → halts protozoal DNA and RNA synthesis.
When combined with sulfonamides (which inhibit dihydropteroate synthase earlier in the pathway), it produces a synergistic, sequential blockade of the folate synthesis pathway.
안전성·주의사항
금기사항
- Known hypersensitivity to pyrimethamine
- Preexisting hematologic disorders (use with extreme caution)
- Pregnancy (potentially teratogenic, weigh risks vs. benefits)
- Pregnancy (teratogenic)
- Pre-existing bone marrow suppression
부작용
- Small animals: Anorexia, malaise, vomiting, depression
- Small animals: Bone marrow depression (anemia, thrombocytopenia, leukopenia)
- Cats: Highly susceptible to adverse reactions (noted 4-6 days after starting combination therapy)
- Horses: Leukopenias, thrombocytopenia, and anemias
- Bone marrow suppression (anemia, leukopenia, thrombocytopenia)
- Lethargy
주의
Hematologic Toxicity: Hematologic effects can develop rapidly. Frequent monitoring is recommended, particularly if therapy persists longer than 2 weeks. Oral administration of folinic acid, folic acid, or Brewer's yeast has been suggested to alleviate adverse effects.
Feline Sensitivity: Some clinicians recommend avoiding its use in cats entirely because of its adverse effect profile.
Pregnancy: Pyrimethamine is teratogenic in rats and fetal abnormalities have been seen in foals. FDA Category C. Weigh risks against benefits. Excreted in maternal milk; consider using milk replacer.
약물 상호작용
Reportedly antagonistic towards the activity of pyrimethamine; clinical significance is unclear.
Synergistic with pyrimethamine in activity against toxoplasmosis and malaria.
Use with pyrimethamine/sulfa is not recommended in humans as adverse effects may be additive, however, this combination has been used clinically in horses.
May increase folate deficiency
May increase folate deficiency
모니터링
- CBC with platelet count (frequent monitoring recommended)
- Clinical efficacy
- Signs of abnormal bleeding or lassitude
- Complete Blood Count (CBC) every 1-2 weeks
- Appetite and body weight
- Signs of bleeding, bruising, or lethargy
약동학
반감기
흡수
No pharmacokinetic data located for veterinary species. In humans, well absorbed from the gut after oral administration.
분포
Distributed primarily to the kidneys, liver, spleen, and lungs. Crosses the blood-brain barrier. Volume of distribution is about 3 L/kg. 80% bound to plasma proteins. Enters milk in levels greater than serum.
대사
Unknown how or where the drug is metabolized, but metabolites are found in the urine.
배설
Excreted in the urine.
과다투여
Reports of acute overdosage in animals were not located. In humans, signs include vomiting, nausea, anorexia, CNS stimulation (including seizures), and hematologic effects.
Treatment recommendations:
- Standard procedures to empty the gut or prevent absorption.
- Parenteral barbiturates for seizures.
- Folinic acid for hematologic effects.
- Long-term monitoring (at least 1 month) of renal and hematopoietic systems.
제품
제형
- Tablets: 25 mg
- 25 mg tablet
인용의약품
- Pyrimethamine Tablets: 25 mg; Daraprim® (GlaxoSmithKline); (Rx)
- Daraprim 25 mg tablets
규제 현황
Often used under the cascade from human medicine.
Listed as a Pharmacy (P) medicine in the provided monograph.
규제 데이터 없음: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
보관·안정성
Store tablets in tight, light-resistant containers. Tablets may be crushed to make oral suspensions. If cherry syrup, corn syrup, or sucrose-containing liquids are used, store the suspension at room temperature and discard after 7 days (sugars adversely affect stability).
보호자 정보
중요: 이 약물은 심각한 기생충 감염을 치료하는 데 사용되며 세심한 모니터링이 필요합니다.
- 지시대로 정확히 투여하십시오: 최대의 효과를 위해 종종 다른 항생제(설파계 약물 등)와 함께 투여됩니다. 복용을 건너뛰지 마십시오.
- 부작용 관찰: 반려동물이 무기력해지거나, 식욕을 잃거나, 구토를 하거나, 비정상적인 출혈이나 멍(창백한 잇몸이나 피부의 붉은 반점 등)의 징후를 보이면 즉시 수의사에게 연락하십시오.
- 고양이 투여의 어려움: 시판되는 알약은 25mg이므로 고양이에게 정확한 용량을 투여하기가 매우 어렵습니다. 또한 알약은 고양이에게 맛이 좋지 않습니다. 수의사는 정확하고 쉬운 투여를 위해 특별히 조제된 액체나 캡슐을 권장할 수 있습니다.
- 임신 경고: 보호자가 임신 중인 경우 이 약물을 만지지 마십시오. 수의사의 명확한 지시가 없는 한 임신 중인 반려동물에게 사용하지 마십시오.
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