IB Chemistry/Medicines and Drugs

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Definitions to Know

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Agonist- Chemical substance that mimics the effects of a neurotransmitter being increased in the brain.

Alginates - Substances that float on the contents of the stomach to produce a neutralizing layer, preventing heartburn

Alkaloid - Nitrogen–containing compound of plant origin containing a heterocyclic ring and a tertiary amine group

Amphetamine - A sympathomimetic drug, which means it mimics the effect of stimulation on the sympathetic nervous system, that is chemically related to adrenaline and were used to treat narcolepsy during WWII and depression and obesity in the 50’s and 60’s

Antacids - simple bases, such as metal oxides, hydroxides, carbonates, or hydrogen carbonates, that combat indigestion by neutralizing the acid, preventing inflammation, relieving pain and discomfort, and allowing the mucus layer and stomach lining to mend; e.g. Al(OH)3, NaHCO3, CaCO3, milk of magnesia (a mixture of MgO and Mg(OH)2

antagonist - Chemical substances that blocks or decreases the reuptake of a certain neurotransmitter in the brain.

Antibacterials - Chemicals which prevent the growth and multiplication of bacteria; the first effective one was dye trypan red (sleeping sickness), then salvarsan (syphilis), then prontosil (strep), then penicillin

Antidepressants - A synthetic chemical drug used to increase the serotonin levels in the brain. Used to treat mood disorders, particular depression. The most common type of antidepressants used are selective serotonin reuptake inhibitors, also known as SSRIs. Although mood disorders are not the direct cause from low serotonin, studies have shown that low serotonin levels are related. A few well known SSRIs most commonly prescribed for patients with depression is Prozac (Fluoxetine), Zoloft (Sertraline), Paxil (Paroxetine), and Luvox (Fluvoxamine). Mild side affects do come along with antidepressants. They normally take about 6- 8 weeks to show effectiveness. Antidepressants are highly recommended to be under the supervision of a psychiatrist as well as therapy.

Anti–foaming agents - Agents used to prevent flatulence; most common is dimethicone

Aspirin - Ethanoate ester of salicylic acid; mild analgesic; anticoagulant, strokes and the recurrence of myocardiac infarction

Bacterium - A micro–organism that is made up of a complex mixture of proteins, sugars, and lipids and contains a single chromosome consisting of DNA in each cell

Breathalyzer - A test for alcohol in the breath the individual in question breathes into a tube containing potassium or sodium dichromate crystals of an orange color; if the crystals turn green, the dichromate has been reduced to Cr+3 by a sufficiently high level of alcohol, generally over the legal limit for driving; “Green does not mean go home; it means go directly to jail, do not pass Go, do not collect $200”; this test is not strong enough to be used in a court of law

Broad spectrum antibiotics - Antibacterials that are effective against a wide range of bacteria

Caffeine - The world’s most widely used stimulant; is present in coffee, tea, chocolate, cola drinks, and some painkillers and other medicines

Depressants - Drugs which depress the central nervous system by interfering with the transmission of nerve impulses in the nerve cells; some common depressants include alcohol, benzodiazepine (BZD), and Prozac

Designer drugs - Drugs created by modifying the structure of an amphetamine

Digestion - The breakdown of food into molecules that can be utilized by individual cells in the body

Ecstasy - A designer drug which relieves Parkinson’s disease but is frequently abused

Effective Dose - The dose required to bring about a noticeable affect in 50 percent of the population

Gastric juices - Mucous, pepsinogen, and hydrochloric acid

Heartburn - GORD, stomach acid refluxes up the oesophagus

Indigestion - Discomforted caused from excessive acid production; caused by overeating, alcohol, smoking, anxiety, and eating certain types of foods in some individuals

Lethal dose - The dose required to kill fifty percent of the animal population, known as the LD50

Mild analgesic - Reduces suffering from pain by decreasing the level of pain

Narrow spectrum antibiotics - Including some penicillins, antibacterials which are effective against only certain types of bacteria

Nicotine - The substance found in tobacco that is largely responsible for causing approximately 1/3 of the world’s population to be addicted to smoking

Pineal gland - A small lump of tissue at the base of the brain that produces melatonin

Risk–to–benefit ratio - The ratio balancing the risks of taking a drug, including side effects, with the benefits garnered from the drug

Side effects - Unwanted repercussions from taking a certain drug

Strong analgesic - Reduces suffering from pain by increasing one’s pain tolerance level; are available only by prescription; most important naturally occurring are morphine and codeine; heroin and Demerol are synthetically produced

Thalidomide - A tranquilizer released in 1958 that was said to cure morning sickness; unrevealed side effects of the drug, which were not revealed until 1961, caused many women who took this drug to give birth to malformed children (teratogenic)

Tolerance - Adaptation of the body to a certain drug; a person who develops tolerance for a drug requires larger and larger doses to achieve the original effect

Common Effects of Several Chemicals

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Alcohol - Antiseptic, depressant-Alcoholism– psychological and physical dependence, violent behavior, family breakdowns, loss of consciousness at high doses, cirrhosis of the liver, liver cancer, dementia, delirium tremens (DT’s) after sudden discontinuation; lethal when taken with benzodiazepines, narcotics, barbiturates, and solvents and increases stomach bleeding when taken with aspirin

Amphetamines - Sympathomimetism, treats narcolepsy, depression, and obesity-Heart rate and breathing increase, tolerance, dependence, appetite down, possible depression, emotional instability

Antacids - Combat excess stomach acid, preventing inflammation, relieving pain and discomfort, allow the mucus layer and stomach lining to heal (or ulcer)-Diarrhea, constipation, possible bone damage, bloating and belching

Antidepressants - Nausea, insomnia, dizziness, sweating, headaches, decrease sex drive, fatigue, dry mouth, constipation and weight gain or loss.

Aspirin - Painkiller, can be taken for arthritis and rheumatism, prevents blood clotting, prevent strokes or the recurrence of heart attacks-Bleeding of the stomach, allergies to it can lead to bronchial asthma, Reye’s disease in children under 12 (rare), overdose can lead to acidosis

Caffeine - Stimulant, diuretic, catalyst in painkillers-Restlessness

Ecstasy - Relieves symptoms of Parkinson’s disease-Mental relaxation, increase sensitivity to stimuli, hallucinations, can be fatal after just a single dose. May damage cells in the brain used to release serotonin creating chemical imbalances which can cause many psychiatric disorders and perhaps, memory loss due to shortening of dentrites.

Morphine - Strong analgesic and painkiller-Constipation

Nicotine - Increases concentration and relieves tension-Addiction, increased heart rate and blood pressure, increased risk of heart disease and coronary thrombosis, withdrawal– craving for tobacco, nausea, weight gain, insomnia, irritability, depression

Opiates (Diethanoylmorphine or heroin) - Even more powerful painkiller than morphine and codeine-Short–term: euphoria, painkilling, nervous system depression, breath and heart rate down, high doses lead to coma/death; Long–term: constipation, loss of sex drive, disruption of menstrual cycle, risk of parenterally–distributed diseases, social problems

Paracetamol (Acetaminophen)- Mild analgesic, preferred over aspirin for children-Renal damage and vascular disorders (rare), overdose can lead to death, renal, hepatic, and cervical damage

Thalidomide - Combats morning sickness-Causes women to give birth to malformed children (teratogenic)

D1.1 Effects of medicine and drugs on the Functioning of the Body

A medicine or drug is any chemical that

• Alters the physiological state (living systems), including consciousness, activity level or coordination • Alters incoming sensory sensations • Alters mood or emotions

Medicine and drugs are generally used to improve health, by helping the body in it's healing process. The mechanism of the drug action still isn't known completely, and the placebo effect can occur, where the body is fooled into healing itself.

D1.2 Stages of research, development, and testing of new pharmaceutical products

This process is very long, and very expensive. Usually, the drug or medicine is either isolated from an existing species, or created chemically. The medicine/drugs is then tested in trails to demonstrate the effectiveness.

Before human trials start, the drugs are tested on animals to determine the lethal dose and the effective dose. After determining these two doses, the therapeutic index can be calculated.

Therapeutic index = LD50/ED50

This compares the therapeutic effects to the toxic effects. For example, if the therapeutic index is 100 then the ration is 100:1, which means that increasing the dose a hundred fold for the effective dose would result in 50 percent death rate.

After the therapeutic index is established, the drug can then move to clinical trials with humans. Usually, this involves volunteers and patients, with half getting a placebo. This trial is observed to see if the drug is helpful and to find the possible side effects.

Drugs usually have unwanted side effects. Side effects change depending on the reason for taking the drug. The severity of the complaints in the trials will help determine if the risk-to-benefit ratio is acceptable. Even if the risk is high, if the drug helps with a life-threatening disease, then the side effects will be more acceptable. The tolerance is also determined.

If it passes the initial clinical trail, then more rigorous testing will occur, with widened use in a variety of clinical situations. If it passes all these trials, then it can be approved by a drug administration for over the counter use or through prescription only.

One case where the problem wasn't stopped was with the drug Thalidomide. The drug was a tranquilizer with the purpose of stopping morning sickness in pregnant women. Severe side effects occured, and it became known that the drug had problems which were shown in earlier clinical trials. The drug continued to be marketed, and was eventually withdrawn years later. The drug caused birth defects, with absent or deformed limbs.


Other Important Facts to Know

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Methods of Administering Drugs

1. Mouth (Oral)

2. Inhalation (tracheal)

3. Through the anus (rectal)

4. Injection (parenteral- Three Types: Intravenous, Subcutaneous, and Intramuscular)

5. Topically (creams, sprays, drops, etc.)

• The [H+] of HCl in the stomach is between 0.03 and 0.003, and the pH 1.5–2.5

• Legal limit for driving is a BAC of 80 mg alcohol per 100 cm3 blood

• 1 unit alcohol = ½ pint beer or lager, 1 glass of wine, 1 measure of spirits

Mechanism of Action of Antibiotics

1. Penicillins and cephalosporins prevent bacteria from making normal cell walls

2. Other antiobiotics act inside the bacteria interfering with the chemical activities essential to their life function

I'm really sorry, but I can't find my notes on Viruses. As soon as I locate them, I will put them in. Good luck! It's really not that hard of an exam if you know what you're doing.


- Lack a cell structure and are more difficult to treat in the body than bacteria

- Viruses consist only of DNA or RNA, and protein

- Antiviral drugs target specific viral infections by causing changes to the cell membrane which prevent the entry of viruses

- Antivirals can also alter the cell's DNA so it cannot be used by the virus or block enzyme activity to prevent viral multiplication

Specific Drugs to Know for Viruses:

- Oseltamivir (Tamiflu) and zanamivir (Relenza) are antivirals for flu that inhibit the enzyme neuraminidase, which allows new viral particles to escape from the host cell and cause infection. They must be taken immediately as symptoms appear or the viral infection will already have spread too far.

- Oseltamivir and zanamivir have similar structures, and act as competitive inhibitors with neuraminidase as their structures are similar to sialic acid, its normal substrate.