Paracetamol (acetaminophen) is generally not considered an NSAID because it has only little anti-inflammatory activity. It treats pain mainly by blocking COX-2 mostly in the central nervous system, but not much in the rest of the body.

Analgesia data from 173 patients in French, Canadian, American, and Australian and New Zealand ICUs suggest that acetaminophen/paracetamol is the most common first-line analgesic (49.1% of patients) ¹⁾.

Paracetamol, an antipyretic frequently employed in patients with cerebral damage, may cause hypotension.

Picetti et al., evaluated the cerebral and hemodynamic effects of intravenous (IV) paracetamol for the control of fever in Neuro-Intensive Care Unit (NICU) patients.

This prospective observational study in which they enrolled 32 NICU patients: Subarachnoid Hemorrhage (SAH, n = 18), Traumatic Brain Injury (TBI, n = 10), Intracerebral Hemorrhage (ICH, n = 2) and Acute Ischemic Stroke (AIS, n = 2).

The administration of paracetamol resulted in a decrease of core body temperature (Tc) (p = 0,0001), mean arterial pressure (MAP) (p = 0,0006), cerebral perfusion pressure (CPP) (p = 0,0033), and jugular venous oxygen saturation (SjVO2) (p = 0.0193), and in an increase of arteriojugular venous difference of oxygen (AVDO2) (p = 0.0012). The proportion of patients who had an infusion of norepinephrine increased from 47 % to 75 % (p = 0.0039 McNemar Test). When intracranial pressure (ICP) at the start of paracetamol infusion (t-0) was compared with the measurement of ICP after 2 h, a significant correlation was observed (r = 0.669, p = 0.0002). This marked and significant correlation can be explained by the fact that for the higher levels of ICP assessed at t-0 (greater than 15 mmHg), they observed a marked reduction of ICP concomitant with the decrease of Tc. No problems related to norepinephrine administration and/or increase in dosage were observed.

Paracetamol administration is effective but exposes patients to hypotensive episodes that must be recognized and treated expeditiously to prevent further damage to the injured brain ²⁾.