At about 4h30 on the afternoon of Saturday, 21 November 1970, not long after Richard Bros’ arrest, the Divisional Surgeon, Dr. Arnold Mendoza, prescribed a course of (Phenergan) promethazine. “A mild sedative”, he later would tell the inquest, “He needed something like this”. For his nervous disposition. He left an envelope with several tablets, Royal blue in colour, and instructed the police to give Bros two tablets every four hours.

For his nervous condition

Paris, 1949. A cab driver, who suffered from allergies and suffered from minor complaints, told his a session with his psychiatrist, , told him of a recent event, which for someone in his profession posed a problem. He had driven through a red light. Not that he had not seen it, but because he did not care. His indifference was not shared with the police officer who pulled him over, and gave him a fine.

The psychiatrist diagnosed fatigue, or drowsiness, accentuated by the antihistamine his patient was taking, promethazine. More fully, promethazine (Phenergan, 3277 R), which at the time was thought to have sedative side effects. It took some time for the realization that it was a tranquilizer. ” promethazine procures ‘ euphoric quietude… Our patients are calm, somewhat somnolent, relaxed and look rested…. even after major operations they are euphoric, never excited, nor complaining and appear to really suffer less.'”

Promethazine overdose

An overdose can lead to serious effects:

Phenothiazes, such as promethazine, act as respirator depressants, worsening hypoventilations. In fact, there are a considerable number of possible serious risks from promethazine or the other phenothiazines

By interfering with CNS metabolism, the drug also favours adverse reactions, such as malignant hyperpyrexia (exceptionally high fever), convulsions, and extrapyramidal reactions Physical symptoms, including “tremor, slurred speech, akathisia ( a movement disorder characterized by a subjective feeling of inner restlessness accompanied by mental distress and an inability to sit still, dystonia (a state of abnormal muscle tone resulting in muscular spasm and abnormal posture); anxiety, distress, paranoia, and bradyphemia (slowness of thought and speech); airway obstructions through spasm of the tongue, or laryngospasm (a rare but frightening experience in which the vocal cords suddenly close when taking in a breath, blocking the flow of air into the lungs.) Phenothiazines act as respiratory depressants, worsening hypoventilation. Phenothiazines were shown to prolong QT intervals, an abnormally long or abnormally short QT interval is associated with an increased risk of developing abnormal heart rhythms and sudden cardiac death. Some of these life-threatening events were associated with cases of sudden death during phenothiazine treatment.

Promethazine dosage norm

Novartis gives the following recommendations for Phenergan (promethazine) dosage:

Antihistamine: 25 mg at bedtime as needed

Sedative-hypnotic: 25 to 50 mg daily

Do not exceed 100 mg daily

A medical Memoranda in the British Journal of Medicine reports:

Serious effects in both children and adults have been recorded after ingestion of between 125 and 350 mg. (Leak, David. Brit. med. J., 1967, 2, 31-32)

Human performance and promethazine

In 1996, NASA published The effects of promethazine on human performance, mood states, and motion sickness tolerance (NASA Technical Memorandum 110420) Subjects were given 25mg or 50 mg of promethazine by injection and given a series of tests at 2hrs and 4hrs. Manual dexterity was severely degraded. At 4hrs, the Blood Alcohol equivalent was 0.135%, significantly higher than the blood alcohol driving limit set in most jurisdictions worldwide.

Note that the maximum dose of the NASA study was 50mg, for below the dosage to which Richard Bros was subjected. This is particularly so given that the half-life of promethazine in the human body is 7 to 11 hours. (J. Quinn et al, The disposition of promethazine in man, J. of Pharmaceutical Pharmacology, 28:59 P (1976) Giving more doses before complete elimination from the body of course brings a increasing amount, which can be approximated by pharmacokinetics analysis.

We will return to ” human performance” implications in a subsequent post, when we discuss the observations of the officer who found the body of Richard Bros.

Simulating suicide

If one wished to murder someone by a simulated suicide by hanging, employing for a ligature or other mechanical means, one would face several problems. For one, it is quite difficult to overwhelm and control a victim who, quite naturally and instinctively, is fighting for his or her life. It likely would take two assailants, and however successful the assailants were, almost certainly signs of the assault would remain. So too would remain contusions and abrasions or lesions on the neck , where the victim attempted to remove the ligature . Signs that would be quite obvious to the medical examiner who performs the autopsy.

The killer, or more likely killers, would want the victim to be unable to defend himself, die quickly, leave no physical evidence that would contradict suicide by hanging.

For which promethazine is well-suited.

While conducting my enquiries in London, I attempted to contact Dr. Mendoza, for clarification on the dosage of promethazine hydrochloride he had prescribed for Richard Bros. I learned that, unfortunately, he was deceased. However, I did speak with his widow, who had been an obstetrics nurse, knowlegible of the drug, commonly prescribed to women about to give birth. She informed me that Dr. Mendoza, who amongst other specialities was a specialist in Obstetrics, was very familiar with promethazine hydrochloride. She also said that he was quite conservative with medication, and certainly would have been so in prescribing the medication for Richard Bros. Which tells us that the evident overdose prescribed that day was intentional.