Over-the-Counter Drugs
People falsely assume that if a drug is sold over the counter, it is immune from drug
interactions or other complications. Over-the-counter drugs are those that are selfprescribed and self-administered for relief of symptoms of self-diagnosed illnesses.
Consumers self-treat 4X more health problems than doctors treat. They spend over $18
billion a year on OTC products. Over half of Americans take at least 2 different
medications daily, along with vitamins and supplements. 58% of survey respondents in
2001 said they had taken an average of 2 OTC medications or supplements in the week
before. 40% said they use an average of 2 such products daily. Yet half of consumers say
they don’t read labels on OTC drugs. The 2 biggest markets are for analgesics and cough,
cold remedies. If you see multiple doctors, you should keep one pharmacist to oversee
any possible interactive effects of drugs prescribed. If your symptoms persist past 20
days, you should see a doctor.
Regulation of drug products began in 1962 when all drugs were mandated to be evaluated
for safety and efficacy. The FDA set up criteria for new drugs and began to review all the
OTC drugs already on the market- 250,000-300,000. These drugs are divided into 26
classes including sedatives, sleep aids, cold remedies, antihistamines, allergy products,
and stimulants. By 2001 the list of classes had grown from 26 to over 100.
A drug is supposed to be sold over the counter unless there is potential toxicity or for
safety reasons it must only be sold by prescription. Often the only difference between an
OTC product and a prescription is the amount of active ingredient per dose. Between
1972 and 1992 20 ingredients were switched to OTC status, including nicotine gum and
patches, and minoxidil, the hair growing medication.
Stimulants can only be marketed with caffeine as the active ingredient. No Doz and
Vivarin are some OTC stimulants. Before this regulation stimulants also included
ephedrine or phenylpropanolamine (PPA). Ephedrine is a sympathomimetic derived
from a Chinese herbal tea and sold as a bronchodilator. The amphetamine molecule was
derived from it. It has been sold in weight control products. Recently ephedrine has been
taken off the market as dangerous, as some consumers have died after ingestion.
Weight-control products became big business in the 1970s with PPA as the active
ingredient. Some included caffeine, but in 1983 the FDA ruled that such combinations
were illegal, since they were not safe. The risk was increased blood pressure due to the
sympathetic stimulation on the CNS. In 2000 the FDA advised that women taking PPA
were at increased risk of bleeding in the brain (hemorrhagic stroke.) Dexatrim was
marketing a natural version containing ma huang (ephedra). Other products have been
tried such as starch blockers, but no measurable effects are seen in weight loss.
Sedatives and sleep aids included Quiet World and Compoz and contained the
acetylcholine receptor blocker scopolamine combined with the antihistamine
methapyrilene. Sleep-Ez and Sominex contained more of these 2 ingredients. Some
antihistamines do produce a sedated state, drowsiness. The FDA accepted methapyrilene
but rejected scopolamine. The sedative effects are increased by alcohol, so don’t take
alcohol with these products.
Analgesics moderate pain. Anesthetics reduce all types of sensation or blocking
consciousness completely. Anesthetics used in surgery or dentistry work in this way.
Analgesics reduce pain selectively without causing a loss of other sensations. They are
divided into 2 groups: opiates and OTC internal analgesics such as acetaminophen,
aspirin, ibuprofen.
Pain comes in 2 types, too. Visceral pain, such as intestinal cramps comes from the nonskeletal parts of the body. Narcotics are useful in reducing pain of this type. Somatic
pain arises from muscle or bone- sprains, headaches, arthritis is reduced by salicylates
(aspirin) and related products. The experience of pain is very individual, varying with
personality, gender, time of day, level of fatigue, anxiety, fear, boredom, fear of more
pain. In placebo based studies, 35% of subjects with pain find their pain relieved by
placebos. This is a high number, but placebos are most effective in stressful situations.
For certain kinds of pain, however, internal analgesics have been shown to be more
effective than placebos.
Aspirin (Salicylates) are the most widely used class of internal analgesics. The American
Indians used a tea brewed from willow bark to reduce fever. In 1838 salicylic acid was
synthesized and in 1859 procedures were developed to make bulk production effective.
Hoffmann in the Bayer Laboratories in Germany synthesized acetylsalicylic acid and
tested it on his father who suffered with serious arthritis. The salicylic acid he had been
using caused serious gastric upset, so Hoffmann was searching for a milder but effective
pain reliever. This product was patented and sold in 1899 as Aspirin. Aspirin is converted
to salicylic acid in the body. Aspirin is more potent than salicylic acid and it irritates the
stomach less and is absorbed more rapidly. In 1915 it became an OTC product.
Aspirin has 3 major purposes: blocks somatic pain, is antipyretic, reducing fever,
and is an anti-inflammatory which reduces swelling, inflammation, and soreness in an
injured area. This is why it is used for arthritis so effectively. Unfortunately the side
effect for many people is gastric irritation. Some aspirin preparations are buffered with
ingredients to neutralize the acidity of aspirin. This actually seems to produce faster relief
by moving the aspirin more rapidly through the system into the intestine. The therapeutic
dose for aspirin is 600 – 1000 mg. Aspirin will induce gastrointestinal bleeding in 70% of
subjects. The blood loss can be enough to produce anemia. It also may erode the gastric
mucosa, producing ulcers or tears in the stomach lining.
The salicylates do not block all types of pain. They are effective against headache
and musculoskeletal aches and pains. They are less effective for toothache and sore throat
and fairly useless in visceral pain or acute pain. Aspirin works on the temperatureregulating area of the hypothalamus to increase heat loss through peripheral mechanisms.
This means vasodilation of peripheral blood vessels and increased perspiration.
Not only does aspirin irritate the stomach, it also inhibits blood clotting. This can
make it a risk for those having surgery, if their bleeding can’t be stopped. This effect can
last 4-7 days. It can be a risk for gestating mothers close to delivery. But it crosses the
placental barrier, so it probably is not safe for pregnant women to take at any time. But
men can use aspirin regularly to decrease clotting, reducing risk of TIA- transient
ischemic attack- a tiny blood clot in the brain or retina- precursors of stroke and damage
to parts of the brain. For men who have had a heart attack, taking an aspirin every other
day has been shown to reduce risk of a second heart attack.
In the 1980s there was found to be a relationship between taking aspirin and
getting Reye’s syndrome following a viral infection. It was rare, but lethal enough to
produce a warning about taking aspirin for a virus. The patients were under age 20, began
vomiting continuously after having had flu or chicken pox. They became disoriented,
showed personality changes, became lethargic, and some entered comas and died or
suffered brain damage. Mortality from Reye’s was 25%.
Aspirin has also been associated with accidental poisonings of children and
suicide attempts. Aspirin is a major cause of emergency room visits.
It modifies the cause of pain. Aspirin blocks the synthesis of prostaglandins,
which are local hormones that are released when cell membranes are distorted or
damaged, injured. The prostaglandins sensitize the neurons to histamines and bradykinin,
which are more slowly released from the damaged tissue. Aspirin has an analgesic effect
in tissues where prostaglandin formation is happening. Aspirin also works in the brain to
decrease heat dissipation through sweating and dilation of peripheral blood vessels by
blocking synthesis of this specific prostaglandin in the anterior hypothalamus in the
brain.
Acetaminophen and phenacetin are related analgesic compounds. Phenacetin was
retired when it was found to cause kidney lesions and dysfunction. Acetaminophen is
equal in power with aspirin in relieving pain and reducing fever. It does not reduce
inflammation, however, so it is not helpful with arthritis. Acetaminophen is marketed as
Tylenol and Datril. Overuse of these drugs can cause liver disorders. It has surpassed
aspirin for drug-related ER visits and drug-related deaths.
Ibuprofen and other NSAIDs- these are powerful anti-inflammatories and are used
widely in treatment of arthritis. Side effects are gastrointestinal, nausea, stomach pain,
cramps. There can be fatal liver damage with overdoses of ibuprofen. Non-steroidal
anti-inflammatory drugs (NSAIDs) include Naproxen as an OTC.
Cold and Allergy products are working against the symptoms produced by viruses- as
many as 100 have been identified as causing cold symptoms. The 2 most common viruses
producing colds are the rhinoviruses and coronaviruses. The rhinoviruses focus on the
upper respiratory tract, causing irritation, coughing, sneezing, and swelling of the mucous
membranes. Mucous membranes release fluids which cause the runny nose and postnasal
drip that irritates the throat. There might also be joint aches and headaches. Fever may be
present early in the infection. The most common means of spread are through the hands
to the nose and mouth. Wash your hands! Even so, only 50% of people exposed to cold
viruses develop symptoms. Many may have some mild symptoms that only last a day, but
never have a full-blown cold. Getting cold or chilled doesn’t seem to affect susceptibility.
So why do we buy cold products if the cold simply has to run its course? To
reduce the miserable symptoms, of course. Three types of drugs are used: 1)
antihistamines for relief of runny nose and sneezing; 2) nasal decongestants for the
swollen membranes in the nose; 3) analgesic-antipyretics for the aches, pains, and fever.
Three of the most popular OTC cold remedies contain the cough suppressant
dextromethorphan. This particular OTC has been abused by teens that get high on large
doses of OTC cough suppressants that contain DM. The effects of 4 – 8 oz. of Robitussin
(720mg DM) include visual/ auditory hallucinations, and even seizures. This altered state
may last several hours. There is also an extreme fit of itching that goes with the effect. It
seems to be quickly addictive in spite of the side effects.
The antihistamines are still being studied as to whether they are actually useful
against cold symptoms. There has been a concern about treating children for colds. Drugs
do not seem to have much greater effect on cold symptoms than placebos. Using
antibiotics is particularly problematic, as more children are building up such resistance to
antibiotics that they may be unable to be treated for a serious infection when it really
counts.
Allergy and Sinus medication also rely on the antihistamine chlorpheniramine maleate
to work on the runny nose. Some sinus meds use pseudoephedrine as decongestants along
with analgesics to reduce swollen sinus passages and treat sinus headache.
St. John’s wort is an herb used for depression and anxiety. Various studies have found
varying degrees of help with these mild conditions.
SAMe is a form of the amino acid methionine and also acts as an antidepressant.
Gingko biloba is used to aid memory, as it is a blood thinner and increases blood
circulation in the brain. There has been seen some improved cognitive functioning in
Alzheimer’s patients.