Clozapine Serum Concentrations Are Disrupted by SARS-CoV-2 Vaccinations

Table 1

Relevant results of blood analyses.

	Reference range	Baseline (d − 4)	Vacc1 (d0)	3d post-Vacc1 (d3)	6d post-Vacc1 (d6)	Recovery (d17)	Vacc2 (d35)	3d post-Vacc2 (d38)	6d post-Vacc2 (d41)
Clozapine (ng/ml)	350–600	383	426	589	387	401	571	854	577
Norclozapine (ng/ml)	—	197	218	277	195	239	325	411	290
Clozapine blood-dosage ratio ((ng/ml)/(mg/day))	0.6–1.2	1.28	1.42	1.96	1.29	1.15	1.52	2.28	1.27
Leukocytes (/nl)	3.5–10	6.93	—	4.85	—	7.2	—	4.92	—
Neutrophils (%)	43–75	54.5	—	58.7	—	66.9	—	52.9	—
CRP (mg/l)	<5	3.5	—	12	—	1.8	—	14	—

Bold letters indicate values above reference. d, day; Vacc1, first vaccination; Vacc 2, second vaccination. Indicates the absence of a steady state since the clozapine dosage has been changed in the previous 5 days. Indicates data from 4 days post Vacc2 (d39) since no routine was obtained from d38.