Severe creatine kinase increase during quetiapine and mirtazapine treatment

Rhabdomyolysis Associated With Mirtazapine and Quetiapine Therapy: A Case Report and Review of the Literature

Rhabdomyolysis has been reported as a rare adverse effect of psychotropic use. This paper presents a case of rhabdomyolysis in a 39-year-old man with depression and substance use disorder. He had been started on quetiapine two months before and mirtazapine two weeks before developing symptoms of pain and weakness. His creatine kinase (CK) was elevated to 5870 U/L, with no other contributing factors elicited. He improved with symptomatic treatment along with cessation of psychotropics. A literature review on rhabdomyolysis associated with quetiapine and/or mirtazapine therapy found 12 cases with quetiapine, one case with mirtazapine, and three cases with quetiapine and mirtazapine combination treatment. The majority were men, aged 19 to 70 years old. There was no clear correlation between dose and maximum CK levels, and the time to onset of symptoms varied from two days to eight months. The proposed mechanism is a serotoninergic or dopaminergic blockade. Rhabdomyolysis associated with quetiapine or mirtazapine can occur even at therapeutic doses and clinicians should be aware of this potentially life-threatening adverse effect.

Severe rhabdomyolysis induced by quetiapine and mirtazapine in a French military soldier

Rhabdomyolysis is a potential complication of psychotropic drugs use and may potentially lead to life-threatening complications, such as an acute renal failure. We describe the case of a 40-year-old military soldier suffering from post-traumatic stress disorder was admitted for an adaptation of his treatment. Mirtazapine was introduced and quetiapine increased. Two days later, the patient presented with severe rhabdomyolysis syndrome. Mirtazapine administration was paused and intravenous hydration commenced. Shortly after the creatine kinase levels decreased enabling mirtazapine to be reintroduced without complication. It is our opinion that 5-hydroxytryptamine 2a serotonergic receptors inhibition (related to mirtazapine and quetiapine) associated with muscle training was responsible for inducing rhabdomyolysis. This must be kept in mind when psychotropic medications are adjusted, especially in an athletic population such as military.

Massive asymptomatic creatine kinase elevation in youth during antipsychotic drug treatment: case reports and critical review of the literature

A massive asymptomatic creatine kinase elevation (MACKE) has been described during antipsychotic exposure in adult psychotic patients without signs of neuroleptic malignant syndrome (NMS), or other most frequent reasons for high creatine kinase (CK) serum level (intramuscular injections, restraints, intense physical activity, dystonic reactions). In this article, we review this clinical condition, and report three cases of MACKE in nonpsychotic, drug-naïve youth during treatment with second generation antipsychotics. The diagnosis of MACKE should be considered after ruling out other possible common reasons of CK increase. The finding of MACKE should indicate a need for weekly monitoring of the CK level only when there are reasons to believe elevated CK is toxic or harmful. Further investigations are recommended when signs and symptoms raise a suspicion of NMS or rhabdomyolysis, including flu-like syndrome, fever, weakness, alteration of consciousness, muscle rigidity, tachycardia, hyper-/hypotension, and dark urine. A drug discontinuation should be considered when possible signs of NMS or rhabdomyolysis are suspected, or in cases of very high and persisting CK levels. Empirical evidence indicates that there is not a "safe" antipsychotic medication; therefore, a switch to another antipsychotic with a different profile is not necessarily a safe option. The spontaneously remitting or intermittent course suggests that the "true" MACKE should be kept distinct from both rhabdomyolysis and NMS. Raising awareness with MACKE may reduce the need for unnecessary diagnosis of NMS or rhabdomyolysis, which may otherwise lead to an unnecessary discontinuation of an effective therapeutic agent.

Antipsychotic-induced elevation of creatine kinase: a systematic review of the literature and recommendations for the clinical practice

RATIONALE

The primary antipsychotic-induced creatine kinase elevation (i.e., not due to neuroleptic malignant syndrome, extrapyramidal symptoms, etc.) is a poorly studied condition.

OBJECTIVES

The aims of the present study were to provide an overview of published cases with antipsychotic-induced creatine kinase elevation and give recommendations for the clinical practice.

METHODS

PubMed and EMBASE were searched for eligible trials, case series, and case reports. We set a threshold at ten times the upper normal limit of the creatine kinase value in order to define an elevation as significant.

RESULTS

The prevalence of significant creatine kinase elevation ranged between 2 and 7%. We found a total of 42 eligible cases. Men were overrepresented in our sample (81%). Patients with myoglobinuria were more likely to be symptomatic (Fisher's exact test, p = 0.006), whereas neither myoglobinuria (Mann-Whitney test, p > 0.10) nor symptoms (Mann-Whitney test, p = 0.64) were related to the magnitude of the creatine kinase (CK) elevation. In the majority of the cases, the antipsychotic medication was discontinued (86%). Forced diuresis was given in 36% of the patients. Eighty-three percent of the patients had no further complications. Only one case was found with a de novo acute renal failure.

CONCLUSIONS

The discontinuation of the antipsychotic medication was a sufficient measure for the CK elevation to subside in the majority of the cases. Cases with myoglobinuria should eventually be treated more aggressively. Further recommendations for the clinical practice are presented.