The inquest heard that Warburton was being medicated with Clozapine, an antipsychotic used to treat severe schizophrenia.
Dr Jane Hetherington, medical director of Linwood Medical Centre where Warburton was a patient, said he was subject to intensive monitoring by community mental health services.
She said Clozapine is prescribed and monitored by specialists and her practice's role in regards to his mental health was limited.