Drug

Fosphenytoin Sodium

118 flagged reaction(s) · 3,404 total co-reports · max PRR 124.5

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	Status Epilepticus	169	124.5	133.3	signal
2	Respiratory Depression	36	24.2	24.5	signal
3	Stevens-johnson Syndrome	62	22.9	23.5	signal
4	Toxic Epidermal Necrolysis	35	19.1	19.4	signal
5	Drug Reaction With Eosinophilia And Systemic Symptoms	46	14.8	15.1	signal
6	Drug Eruption	31	14.5	14.6	signal
7	Drug Ineffective For Unapproved Indication	98	14.5	15.0	signal
8	Generalised Tonic-clonic Seizure	28	14.1	14.2	signal
9	Erythema Multiforme	15	13.2	13.3	signal
10	Encephalopathy	37	12.4	12.6	signal
11	Grand Mal Convulsion	14	12.3	12.4	signal
12	Epilepsy	45	12.1	12.3	signal
13	Ventricular Tachycardia	24	11.9	12.0	signal
14	Cardiac Arrest	119	11.8	12.3	signal
15	Vitamin D Deficiency	13	11.0	11.0	signal
16	Seizure	151	10.8	11.4	signal
17	Electrolyte Imbalance	15	10.7	10.8	signal
18	Brain Oedema	16	10.4	10.5	signal
19	Hyperbilirubinaemia	13	10.4	10.4	signal
20	Neuroleptic Malignant Syndrome	15	10.4	10.4	signal
21	Posterior Reversible Encephalopathy Syndrome	12	10.4	10.4	signal
22	Rhabdomyolysis	52	10.3	10.5	signal
23	Altered State Of Consciousness	26	9.9	10.0	signal
24	Drug Level Decreased	12	9.6	9.7	signal
25	Bradycardia	60	9.3	9.5	signal
26	Cardiogenic Shock	16	9.2	9.3	signal
27	Bacteraemia	13	9.1	9.1	signal
28	Myoclonus	13	9.0	9.0	signal
29	Convulsion	61	8.6	8.8	signal
30	Unresponsive To Stimuli	27	8.6	8.7	signal
31	Acute Respiratory Failure	20	8.6	8.6	signal
32	Blood Creatine Phosphokinase Increased	30	8.4	8.5	signal
33	Hepatic Function Abnormal	38	8.4	8.5	signal
34	Metabolic Acidosis	32	8.3	8.4	signal
35	Ataxia	12	8.3	8.3	signal
36	Circulatory Collapse	16	7.7	7.7	signal
37	Multi-organ Failure	16	7.5	7.5	signal
38	Drug Level Increased	15	7.4	7.5	signal
39	Hypocalcaemia	17	7.4	7.4	signal
40	Hemiparesis	15	7.2	7.3	signal
41	Delirium	30	7.1	7.2	signal
42	Mental Status Changes	24	7.1	7.2	signal
43	Subdural Haematoma	12	6.9	6.9	signal
44	Hypotonia	8	6.6	6.6	signal
45	Hepatic Failure	24	6.5	6.6	signal
46	Hypothermia	8	6.5	6.5	signal
47	Sedation	20	6.3	6.3	signal
48	Cardio-respiratory Arrest	32	6.2	6.3	signal
49	Drug Resistance	19	6.1	6.1	signal
50	Hepatic Cytolysis	9	6.1	6.1	signal
51	Pneumonia Aspiration	18	5.9	6.0	signal
52	Brain Injury	7	5.7	5.7	signal
53	Respiratory Arrest	19	5.6	5.6	signal
54	Serotonin Syndrome	13	5.6	5.6	signal
55	Acute Respiratory Distress Syndrome	12	5.6	5.6	signal
56	Therapy Non-responder	30	5.5	5.6	signal
57	Coagulopathy	11	5.4	5.5	signal
58	Treatment Failure	54	5.4	5.5	signal
59	Cerebral Infarction	16	5.4	5.4	signal
60	Coma	31	5.3	5.4	signal
61	Ileus	8	5.3	5.4	signal
62	Respiratory Failure	47	5.3	5.4	signal
63	Disseminated Intravascular Coagulation	9	5.2	5.3	signal
64	Sinus Tachycardia	9	5.2	5.2	signal
65	Eosinophilia	11	5.2	5.2	signal
66	Thrombotic Microangiopathy	6	5.1	5.1	signal
67	Renal Tubular Necrosis	6	5.0	5.0	signal
68	Drug Interaction	93	4.8	5.0	signal
69	Neurotoxicity	10	4.7	4.7	signal
70	Hypotension	114	4.7	4.8	signal
71	Drug-induced Liver Injury	17	4.5	4.6	signal
72	Blood Pressure Decreased	36	4.5	4.5	signal
73	Gamma-glutamyltransferase Increased	12	4.4	4.5	signal
74	Cognitive Disorder	25	4.4	4.4	signal
75	Depressed Level Of Consciousness	21	4.4	4.4	signal
76	Rebound Effect	6	4.3	4.4	signal
77	Electrocardiogram Qt Prolonged	19	4.3	4.4	signal
78	Sinus Bradycardia	5	4.2	4.2	signal
79	Renal Failure Acute	22	4.2	4.2	signal
80	Toxicity To Various Agents	84	4.1	4.2	signal
81	Skin Reaction	7	4.1	4.1	signal
82	Subarachnoid Haemorrhage	5	4.0	4.0	signal
83	Medication Error	27	4.0	4.0	signal
84	International Normalised Ratio Increased	14	4.0	4.0	signal
85	No Therapeutic Response	6	4.0	4.0	signal
86	Shock	11	4.0	4.0	signal
87	Agitation	35	3.9	3.9	signal
88	Accidental Overdose	17	3.8	3.8	signal
89	Therapy Partial Responder	7	3.8	3.8	signal
90	Lactic Acidosis	14	3.6	3.6	signal
91	Cholestasis	8	3.4	3.4	signal
92	Drug Ineffective	536	3.3	4.0	signal
93	Haemorrhage Intracranial	6	3.3	3.3	signal
94	Toxic Skin Eruption	4	3.3	3.3	signal
95	Angioedema	17	3.2	3.2	signal
96	Rash Generalised	10	3.1	3.1	signal
97	Premature Delivery	6	3.1	3.1	signal
98	Premature Baby	11	3.0	3.0	signal
99	Cerebral Haemorrhage	13	3.0	3.0	signal
100	Dialysis	5	2.9	2.9	signal
101	Fluid Overload	5	2.8	2.8	signal
102	Exposure During Pregnancy	21	2.8	2.8	signal
103	Brain Neoplasm	3	2.7	2.7	no signal
104	Poisoning	4	2.6	2.6	no signal
105	Laceration	3	2.6	2.6	no signal
106	Maternal Exposure During Pregnancy	23	2.1	2.2	signal
107	Metastases To Central Nervous System	3	1.9	1.9	no signal
108	Akathisia	3	1.8	1.8	no signal
109	Foetal Exposure During Pregnancy	17	1.7	1.7	no signal
110	Overdose	45	1.7	1.7	no signal
111	Drug Prescribing Error	4	1.7	1.7	no signal
112	Drug Dispensing Error	3	1.6	1.6	no signal
113	No Adverse Event	31	1.4	1.4	no signal
114	Drug Effective For Unapproved Indication	5	1.4	1.4	no signal
115	Suicide Attempt	10	1.4	1.4	no signal
116	Pharmaceutical Product Complaint	4	1.2	1.2	no signal
117	Intentional Overdose	9	1.2	1.2	no signal
118	Completed Suicide	10	1.0	1.0	no signal