CerefolinNAC (CFLN-NAC) contains L-methylfolate (6 mg), methylcobalamin (2 mg), and N-acetylcysteine [NAC] (600 mg) [Pamlab 2017]. Dizziness and lightheadedness have not heretofore been described with use of CFLN-NAC.

Case Study: A 64 year old right-handed female was started on CFLN-NAC for smell and taste issues. Over a three day period, she experienced a gradual increase in dizziness. This was a non-vertiginous lightheadedness, so severe that she was unable to walk, and would lie down the entire day to alleviate the dizziness. It was associated with nausea, but without any vomiting or falls. The dizziness would come and go, last for several hours, and was 9/10 in severity.

She admits to a past history of epochs of vertigo. The vertigo occurred three times with nausea and vomiting 13 years, 11 years, and 4 years prior to presentation. She also developed a constant, bilateral, high-pitched tinnitus 14 years prior to presentation, which obstructs her hearing. It is level 3/10 in intensity during the night and in the quiet. There were no alleviating or aggravating factors. Acupuncture was without effect, and she denies any ear pain. After ceasing CFLN-NAC for three days, a gradual reduction of dizziness to baseline ensued.

Abnormalities in Physical Examination: General: Decreased blink frequency and hypokinesia. Cranial Nerve III, IV, VI: Saccadization of horizontal eye movements. Motor Examination: Tone: 1+ cogwheel rigidity in both upper extremities, left more than right. Drift Test: Bilateral Abductor Digiti Minimi sign with cerebellar spooning. Reflexes: Absent quadriceps femoris and Achilles bilaterally. Positive Hoffman reflex bilaterally. Neuropsychiatric Testing: Go-No-Go Test: 6/6 (normal). Animal Fluency Test: 19 (normal). Reliable Digit Span: 10 (normal). Clock Drawing Test: 4 (normal). Center for Neurologic Study Lability Scale: 10 (normal). Other: Audiometry and Fiberoptic Endoscopy: normal. MRI of the brain with and without contrast was normal.

None of the individual components in CFLN-NAC have been reported to precipitate dizziness [Pamlab 2017]. The non-vertiginous nature of the dizziness makes it unlikely to be due to vestibular involvement, raising the spectre of this drug having an impact on the autonomic nervous system. While a nocebo effect could be in action, this is unlikely since dizziness was not presented as a potential side effect on initiation of the medication. In addition, methylcobalamin can cause hyperviscosity syndrome, but due to an absence of visual disturbances and altered mental status, it is also improbable. The relatively rapid onset with initiation and resolution upon discontinuation of this medication strongly suggests that it is not a coincidence, rather an origin for the dizziness. Those who are treated with CFLN-NAC should be queried as to new onset dizziness. For those already dizzy, one should consider other treatment options.

Smell and Taste Treatment and Research Foundation