Drug

Pyrimethamine

51 flagged reaction(s) · 688 total co-reports · max PRR 29.8

Important: Reactions below are the flagged terms from this drug’s FAERS report history (min. 3 co-reports per term) — PRR/ROR indicate disproportionality in spontaneous reporting, not causation. Data from FDA FAERS via openFDA. Last recalculated: 2026-09-14.

	Reaction	Co-reports (a)	PRR	ROR	Signal
1	Clostridium Difficile Colitis	19	29.8	30.2	signal
2	Lymphopenia	23	27.2	27.7	signal
3	Bone Marrow Failure	33	26.9	27.6	signal
4	Pancytopenia	87	26.0	27.9	signal
5	Pneumocystis Jirovecii Pneumonia	11	18.3	18.5	signal
6	Nephropathy	10	17.7	17.9	signal
7	Drug Resistance	26	16.8	17.2	signal
8	Hepatic Cytolysis	12	16.3	16.5	signal
9	Central Nervous System Lesion	13	15.6	15.8	signal
10	Drug Reaction With Eosinophilia And Systemic Symptoms	23	15.0	15.2	signal
11	Flank Pain	8	14.2	14.3	signal
12	Hepatocellular Injury	12	14.0	14.2	signal
13	Toxic Epidermal Necrolysis	12	13.2	13.4	signal
14	Petechiae	8	12.8	12.9	signal
15	Agranulocytosis	14	12.6	12.7	signal
16	Muscle Spasticity	9	12.1	12.2	signal
17	Cholestasis	13	11.3	11.4	signal
18	Stevens-johnson Syndrome	14	10.5	10.6	signal
19	Coagulopathy	10	10.0	10.1	signal
20	Rash Papular	13	9.6	9.7	signal
21	Neuralgia	14	9.6	9.7	signal
22	Leukopenia	27	9.0	9.2	signal
23	Neutropenia	72	8.8	9.3	signal
24	Ataxia	6	8.4	8.4	signal
25	Myoclonus	6	8.4	8.4	signal
26	Abscess	8	8.3	8.4	signal
27	Pancreatitis	24	7.5	7.7	signal
28	Myocardial Ischaemia	5	7.2	7.3	signal
29	Grand Mal Convulsion	4	7.1	7.1	signal
30	Haemorrhage Intracranial	6	6.7	6.7	signal
31	Breast Pain	4	6.2	6.3	signal
32	Generalised Tonic-clonic Seizure	6	6.1	6.1	signal
33	Premature Baby	11	6.1	6.1	signal
34	Cytomegalovirus Infection	6	6.0	6.0	signal
35	Status Epilepticus	4	5.9	5.9	signal
36	Eosinophilia	6	5.7	5.7	signal
37	Cytopenia	4	5.6	5.6	signal
38	Libido Decreased	4	5.4	5.4	signal
39	Eructation	6	5.2	5.3	signal
40	Visual Acuity Reduced	10	5.0	5.0	signal
41	Toxic Skin Eruption	3	4.9	4.9	signal
42	Uveitis	4	4.9	4.9	signal
43	Drug Level Decreased	3	4.9	4.9	signal
44	Myelosuppression	9	4.4	4.4	signal
45	Maternal Exposure During Pregnancy	23	4.3	4.4	signal
46	Premature Delivery	4	4.2	4.2	signal
47	Tooth Loss	5	4.0	4.0	signal
48	Foetal Exposure During Pregnancy	18	3.7	3.7	signal
49	Bone Density Decreased	7	3.7	3.7	signal
50	Drug Exposure During Pregnancy	5	2.4	2.4	no signal
51	Gynaecomastia	4	2.1	2.1	no signal