Prednisone: The patient's symptoms of acute psychosis, insomnia, and hearing voices, along with restlessness and rapid, pressured speech, are consistent with steroid-induced psychosis. Prednisone, a corticosteroid, is known to cause psychiatric symptoms, including psychosis, especially in elderly patients or at high doses.

Methotrexate: Although less common, methotrexate can cause neurological and psychiatric side effects, including psychosis, especially in patients with renal impairment or at high doses. However, this is less likely compared to prednisone-induced psychosis.
Doxycycline: While doxycycline is not typically associated with psychosis, it can cause CNS side effects such as hallucinations and psychosis in rare cases, particularly in patients with a history of mental health disorders.

Cetirizine: Although cetirizine is generally considered safe, it can cause CNS depression, including somnolence and, in rare cases, hallucinations, especially in elderly patients or when combined with other sedating medications. While unlikely to cause psychosis, it's essential to consider in the differential diagnosis due to its potential for CNS effects.

Bullous pemphigoid: While bullous pemphigoid itself is not typically associated with psychosis, it's essential to consider the possibility of an underlying neurological or autoimmune condition that could be contributing to the patient's symptoms. However, this would be a rare and unlikely cause of acute psychosis in this patient.