Ritalin lung

Ritalin lung describes pulmonary changes induced by intravenous exposure to talc-containing methylphenidate, commercially known as Ritalin.

Epidemiology

Methylphenidate is prescribed primarily for attention deficit hyperactivity disorder (ADHD) and narcolepsy, the latter being the only licensed indication in adults. It is in the piperidine class and is a structural analogue of amphetamine. It is used globally and marketed under several different brands, a well-known one being Ritalin. Off-label use forms an increasingly large proportion of prescriptions ⁵.

Pathology

It has not been fully elucidated why emphysematous changes develop with intravenous administration of talc-containing methylphenidate ⁶. It has been suggested that exposure to talc either results in alveolar destruction via talc granulomatosis or that there is a secondary infection relating to talc exposure resulting in production of elastases resulting in alveolar destruction ⁶. However, similar emphyematous changes are not noted in intravenous administration of other talc-containing drugs, suggesting that methylphenidate may inherently play a role in the pathogenesis of emphysema as well ⁶.

Radiographic features

CT

HRCT chest classically shows pan-lobular emphysematous change ^1,4.

Differential diagnosis

General imaging differential considerations include:

• alpha-1-antitrypsin deficiency: lung changes can be almost indistinguishable on imaging ¹
• vanishing lung syndrome: tends to have more giant bullous spaces with para-septal empysema ³