Augmented (Exaggeration of drug's primary effect, e.g., Bleeding with anticoagulants)

Bizarre (Novel and unexpected response, e.g., Anaphylaxis to penicillin)

Chronic (Reaction due to chronic drug use, e.g., Osteonecrosis with bisphosphonates)

Delayed (Reaction occurring after drug use, characterized by a long latency period between drug exposure and clinical manifestation, e.g., Leukopenia from chemotherapy)

End-fused (Reaction upon drug withdrawal, e.g., Seizures after stopping phenytoin)

Failure of efficacy (Drug doesn't achieve the desired effect, e.g., Antibiotic resistance in bacterial infection)