Thrombocytopenia with quetiapine: two case reports, one with positive rechallenge

Antipsychotic-induced thrombocytopenia is generally rare, but seems to occur more frequently with quetiapine. Accordingly, the relative risk of thrombocytopenia can be described as very rare with loxapine and clozapine (< 0.01%), uncommon with risperidone (≥ 0.1%, < 1%), but very common with quetiapine (≥ 10%). However, very few cases are reported in the literature,^{1 2 3 4} with one published case of idiopathic thrombocytopenic purpura,¹ and it remains unclear whether rechallenge may be considered.

Patient no. 1 was a 78-year-old male hospitalized for depressive syndrome and treated with mirtazapine 45 mg/day, valpromide 1,000 mg/day, and oxazepam 30 mg/day. Quetiapine was added at 50 mg/day, while mirtazapine was reduced to 30 mg/day. Laboratory tests carried out the following day and 5 days after the start of treatment with quetiapine revealed platelet counts of 100,000/mm³ and 56,000/mm³ respectively. Two further measurements were obtained, 8 days and 28 days after discontinuing treatment with quetiapine, showing higher platelet levels of 85,000/mm³ and 120,000/mm³ respectively.

Patient no. 2 was a 72-year-old female hospitalized for personality disorders with hallucinations and treated with aripiprazole 15 mg/day, clonazepam 0.6 mg/day, valproic acid 1,500 mg/day, furosemide 40 mg/day, lisinopril 20 mg/day, nebivolol 5 mg/day, and amlodipine 10 mg/day. During her hospitalization, aripiprazole was stopped and quetiapine 50 mg/day was introduced. Tests performed 3 months after initiating treatment with quetiapine were notable for a platelet count of 107,000/mm³. Six days later, a second test was carried out, and the platelet count was down to 95,000/mm³. Treatment with quetiapine was suspended for 3 days, following which the platelet count went back up to 120,000/mm³. The psychiatrist reintroduced quetiapine and scheduled a control platelet test 5 days later, which showed a decrease to 84,000/mm³. In view of this positive rechallenge, quetiapine was discontinued definitively. Fifteen days after quetiapine discontinuation, the platelet count was 123,000/mm³.

In both situations, no other clinical or iatrogenic parameter seemed to account for the onset of thrombocytopenia. To our knowledge, the second patient described herein is the first case of quetiapine-induced thrombocytopenia with positive rechallenge to be in the literature.

References

• ¹
  Huynh M, Chee K, Lau DH. Thrombotic thrombocytopenic purpura associated with quetiapine. Ann Pharmacother. 2005;39:1346-8.
• ²
  Shankar BR. Quetiapine-induced leucopenia and thrombocytopenia. Psychosomatics. 2007;48:530-1.
• ³
  Perrella C, Carrus D, Costa E, Schifano F. Quetiapine for the treatment of borderline personality disorder; an open-label study. Prog Neuropsychopharmacol Biol Psychiatry. 2007;31:158-63.
• ⁴
  Handoo I, Perales M, Klaus N, Khan AY. Thrombocytopenia secondary to the use of quetiapine. J Child Adolesc Psychopharmacol. 2010;20:453-5.

Publication Dates

• Publication in this collection
  Dec 2015

History

• Received
  24 June 2015
• Accepted
  11 July 2015