Chapter 10 - Drugs

Learning Outcomes

After reading through this chapter, you should be able to:

  • Name problems associated with sleeping pills.
  • Explain the difference between prescription and over-the-counter drugs.

Prescription drugs

Some prescription drugs can affect your ability to drive or operate heavy machinery. They may also interact with existing fatigue levels and other drugs (including alcohol), further affecting your performance.

If you take prescription medication:

  • ask your doctor about possible interactions with other drugs
  • ask your doctor about the drug’s effects on performance, such as your ability to drive and operate machinery
  • tell your supervisor what you are taking so they are aware of your situation (depending on the policies and regulations in your workplace)
  • remember anaesthetics are prescription drugs that can show a positive result on a screening test – inform your supervisor if you’ve had an anaesthetic recently

Drugs that come with a warning not to drive or operate heavy machinery include:

  • angiotensin (such as Losartan, Valsartan or Candesartan for blood pressure)
  • antihistamines (Benadryl, Claritin, or Reactine for allergies)
  • barbiturates (Amytal, Seconal, and Tuinal for sleep and anxiety)
  • benzodiazepines (diazepam, alprazolam, and triazolam for sleep and anxiety)
  • monoamine oxidase inhibitors (Nardil and Parnate for depression)
  • phenothiazines (Mellaril and Thorazine for mental disorders)

Always check the warning labels on the packaging of your medication and ask your doctor or pharmacist if you are unsure.

Over-the-counter drugs

Some over-the-counter drugs used for pain relief or colds and flu may increase drowsiness and fatigue-related symptoms. If you are unsure about the drug you are taking, talk to your pharmacist or tell your supervisor so they are aware of your situation.

Some employees who work irregular schedules and have difficulty sleeping purchase over-the-counter sleeping pills. Examples of this type of medication include Nytol, Sominex, and Sleep-eze. Various antihistamines that cause drowsiness are sometimes used to help the onset of sleep. While these drugs can be effective for getting to sleep, they can also cause increased sleepiness the following day. Use of these drugs is better avoided where possible, and limited to no more than two nights in a row.

There are also over-the-counter drugs available to increase alertness. These include caffeine-based tablets or capsules (such as No-doz and Vivarin) and pseudoephedrine, which is a decongestant (such as Sudafed). While both can be effective in increasing alertness and decreasing fatigue-related symptoms, they also have side effects. Caffeine is a diuretic, which can dehydrate the body. If taken within four hours of going to bed, it can make it harder to fall sleep. Pseudoephedrine can cause increased anxiety levels, heart palpitations, and trouble sleeping. These symptoms have the potential to affect safety and work performance. It is recommended that use of stimulants be limited

How drugs work

Drugs are taken into the body through the mouth (ingestion), blood (injection), or nose (inhalation). After they enter the bloodstream, they act on the brain. Drugs are eliminated from the body through the liver and kidneys into the urine. Drug effects vary not only from person to person; they can also vary for the same person depending on time of day, mood, tiredness, and the amount of food eaten. A person might get drunk on just a few beers one night but be hardly affected by the same amount on another night. Age, gender, and size of a person also influence the overall impact of drugs and the rate of recovery.


Sleeping pills and sedatives (benzodiazepines)


Benzodiazepines are a group of synthetic drugs prescribed by a medical practitioner mostly for the treatment of insomnia and anxiety. There are more than 30 different types available. They are taken orally or, more rarely, by injection. Some of the more common forms include:

  • Valium
  • Serapax
  • Rohypnol
  • Librium
  • Mogadon
  • Temazepam

Drug effects

Some benzodiazepines last as little as four to six hours, while others last as long as two to three days.

They are known to:

  • relieve anxiety and reduce muscle tension, producing a feeling of calmness and relaxation 
  • cause sedation, drowsiness, blurred vision, and affected speech

In high doses, benzodiazepines produce symptoms similar to alcohol. In overdose situations they can cause unconsciousness, coma, and death. This is more likely to occur if benzodiazepines are combined with alcohol or other depressant drugs.

Health effects

Due to the tolerance and dependency effects of benzodiazepines, people are generally advised to take them for only short periods. Long-term usage can produce symptoms of:

  • lethargy
  • irritability
  • lack of motivation
  • nausea
  • headaches
  • disturbed sleep
  • increased appetite
  • depression loss of muscle and speech coordination

You can develop dependency on benzodiazepines after more than one week of use. This means that you:

  • require higher doses to achieve the same effect
  • will suffer physical withdrawal if you stop taking the drug – some people take up to a week before they begin to experience any withdrawal effect.

Once you stop taking benzodiazepines, withdrawal symptoms are common and may last up to a few weeks.

These symptoms include:

  • headaches
  • nervousness
  • poor appetite
  • disturbed sleep
  • sweating
  • anxiety
  • vomiting
  • muscle spasms
  • depression
  • flu-like symptoms

Performance effects

In general these drugs adversely effect:

  • fine motor skills
  • cognitive functioning
  • alertness
  • learning behaviour

They should not be taken when driving or operating machinery or in any other safety critical situation. They impair your ability to judge whether you are physically or mentally affected. Benzodiazepine use has been associated with hangover type symptoms on waking. Users often report grogginess and drowsiness after using benzodiazepines. These effects could have implications for work safety. Chronic use can lead to impairment that persists long after you stop taking the drug. However, most users show improvements once they are no longer taking the drug.

Interactive effects

Combined with alcohol or other depressants in large doses, benzodiazepines exaggerate central nervous system depression, which can lead to respiratory suppression and death.

Indicators of benzodiazepine use

A person who takes benzodiazepines may show symptoms similar to those under the influence of alcohol. When used as a sleeping aid, benzodiazepines may produce hangover effects. That is, you may appear sluggish and show some mental confusion first thing in the morning. Some of the benzodiazepines, such as Rohypnol, cause memory loss during the time they are active.

Clearance times

In general, the time the body takes to clear the drugs varies between one and seven days depending on the drug and dosage. As you age, clearance times for long acting benzodiazepines (like Valium) can greatly increase from a few days to a month. For people who abuse benzodiazepines, it may take up to six weeks for their systems to clear.


checkmark Knowledge Check

  • Name three problems associated with sleeping pills.
  • How does age affect the body’s response to drugs?
  • What is the difference between a prescription drug and a non-prescription drug?
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