ํผ๋ฆฌ๋ฉํ๋ฏผ ๋ฐ ์คํ๋์์ง
**ํผ๋ฆฌ๋ฉํ๋ฏผ ๋ฐ ์คํ๋์์ง(Pyrimethamine and sulfadiazine)**์ ์๋์ง ํจ๊ณผ๋ฅผ ๋ด๋ ํญ๊ท ๋ฐ ํญ์์ถฉ ๋ณตํฉ์ ๋ก, ์์ํ์์๋ ์ฃผ๋ก *Sarcocystis neurona*์ ์ํด ์ ๋ฐ๋๋ **๋ง ์์ถฉ์ฑ ์ฒ์๋์ผ(EPM)** ์น๋ฃ์ ์ฌ์ฉ๋ฉ๋๋ค. * **์๋์ง ์์ฉ:** ์คํ๊ณ ์ฝ๋ฌผ๊ณผ ๋์๋ฏธ๋ ธํผ๋ฆฌ๋ฏธ๋๊ณ ์ฝ๋ฌผ์ ๊ฒฐํฉํ์ฌ ์ฝ์ฐ ํฉ์ฑ ๊ฒฝ๋ก๋ฅผ ์ฐ์์ ์ผ๋ก ์ฐจ๋จํจ์ผ๋ก์จ ๊ฐ์์ฑ์ด ์๋ ์์ถฉ๊ณผ ์ธ๊ท ์ ์น๋ช ์ ์ธ ํจ๊ณผ๋ฅผ ๋ํ๋ ๋๋ค. * **ํ๊ฐ ์ธ ์ฌ์ฉ(Off-label Uses):** FDA์์๋ ๋ง์๊ฒ๋ง ์น์ธ๋์์ผ๋, ์๋๋ฌผ ์์์์๋ ๊ณ ์์ด์ **ํก์ํ๋ผ์ค๋ง์ฆ(Toxoplasmosis)**์ด๋ ๊ฐ์ **๋ค์ค์คํฌ๋ผ์ฆ(Neosporosis)**๊ณผ ๊ฐ์ ์ค์ฆ ์์ถฉ ๊ฐ์ผ ์น๋ฃ๋ฅผ ์ํด ํ๊ฐ ์ธ๋ก ์ฌ์ฉ๋๊ธฐ๋ ํฉ๋๋ค. * **์์์ ์ฃผ์์ฌํญ:** EPM ์น๋ฃ์๋ ์ฅ๊ธฐ๊ฐ(๋ณดํต 3~9๊ฐ์)์ ํฌ์ฝ์ด ํ์ํฉ๋๋ค. ์ ์ ์ ์ธ ์ฝ์ฐ ๊ฒฐํ์ผ๋ก ์ธํ ๊ณจ์ ์ต์ ์ํ์ด ์์ผ๋ฏ๋ก ์์์ฌ์ ์ธ์ฌํ ๋ชจ๋ํฐ๋ง์ด ํ์์ ์ ๋๋ค.
์์ฉ ๊ธฐ์ : This combination exerts its antiprotozoal and antibacterial effects through a **sequential blockade** of the folic acid synthesis pathway, which is essential for nucleic acid (DNA/RNA) production in the parasite: 1. **Sulfadiazine** acts as a structural analogue of para-aminobenzoic acid (**PABA**). It competitively inhibits the enzyme **dihydropteroate synthase**, blocking the conversion of PABA โ **dihydrofolic acid (DFA)**. 2. **Pyrimethamine** specifically targets and inhibits the enzyme **dihydrofolate reductase**, blocking the conversion of DFA โ **tetrahydrofolic acid (THFA)** (the active form of folate). > **Pharmacological Pearl:** Pyrimethamine has a much higher affinity for protozoal dihydrofolate reductase compared to bacterial or mammalian forms, making it highly effective against protozoal parasites like *Sarcocystis neurona* and *Toxoplasma gondii*.
๋๋ฌผ ์ข ๋ณ ์ฉ๋
- Treatment of EPM ยท 20 mg/kg sulfadiazine with 1 mg/kg pyrimethamine; equivalent to 4 mL of ReBalance suspension per 50 kg (110 lb) body weight ยท PO ยท once daily ยท 90-270 days (based upon clinical response) ยท Administer at least 1 hour before feeding with hay or grain. Administer using a suitable oral dosing syringe; insert nozzle through the interdental space and deposit the dose on the back of the tongue.
- Maintaining clinical remission (for horses that have had two relapses) ยท pyrimethamine/sulfadiazine ยท PO ยท twice weekly (first and fourth day of each week) ยท Ongoing ยท After completing regular therapy for EPM.
์ฉ๋์ ๋ฉดํ ์์ ์ ๋ฌธ๊ฐ๋ฅผ ์ํ ์์ ์ฐธ๊ณ ์๋ฃ์ ๋๋ค. ํญ์ ์ต์ ๋ผ๋ฒจ๊ณผ ๊ฐ๋ณ ํ์์ ๋ํด ํ์ธํ์ญ์์ค.
ํฌ์ฌ ๊ฒฝ๋ก
๊ธ๊ธฐ
- Hypersensitivity to pyrimethamine or sulfadiazine
- Horses intended for human consumption
์ด์๋ฐ์
- Bone marrow suppression (anemia, leukopenia, neutropenia, thrombocytopenia)
- Reduced appetite or anorexia
- Loose stools or diarrhea
- Urticaria (hives)
- Treatment crisis (temporary worsening of neurologic signs due to parasite die-off)
- CNS effects (seizures, depression - though often secondary to the underlying EPM)
์ฝ๋ฌผ ์ํธ์์ฉ
- Antacids ยท May decrease the bioavailability of sulfonamides if administered concurrently.
- Highly protein-bound drugs (e.g., methotrexate, phenylbutazone, thiazide diuretics, salicylates, probenecid, phenytoin, warfarin) ยท Sulfonamides may displace other highly bound drugs, potentially increasing their free (active) plasma concentrations and risk of toxicity.
- p-Aminobenzoic acid (PABA) ยท Reportedly antagonistic towards the activity of pyrimethamine; clinical significance is unclear.
- Trimethoprim ยท Use with pyrimethamine/sulfa is not recommended in humans as adverse effects may be additive; however, this combination has been used clinically in horses.
๋ชจ๋ํฐ๋ง
- CBC (including platelets): baseline and at least monthly during therapy
- GI adverse effects (appetite, stool consistency)
- Clinical Efficacy: Improvement in neurologic signs
- CSF Western Blot test (monitoring for negative status)
๊ณผ์ฉ๋
Acute overdosage information (>2X) in horses is not well documented. When administered at **2X the labeled dose for 92 days**, signs included loose stools, slight increases in ALP, declines in red blood cell parameters (RBC, HCT, Hgb, PCV), and depressed appetite. Treatment should be supportive and symptomatic.
VetSheet ์ฝ๋ฌผ ๋ ํผ๋ฐ์ค๋ ๋ฉดํ ์์ ์ ๋ฌธ๊ฐ๋ฅผ ์ํ ์์ ์์ฌ๊ฒฐ์ ๋ณด์กฐ ๋๊ตฌ์ด๋ฉฐ, ์ ๋ฌธ์ ํ๋จ์ด๋ ์ ์กฐ์ฌ์ ์ต์ ๋ผ๋ฒจ์ ๋์ ํ์ง ์์ต๋๋ค.