As with any drug, ATENOLOL
is after all a xenebiotic for the body. Inherently, with
the benefits of its pharmacology are its adverse side-effects.
Despite the benefits, there are secondary interactions and
bioactive pathways, which can lead to a diversity of implications.
On the outset, side effects
from ATENOLOL are rarely observed albeit
diverse in their symptoms. The following is a list of possible
side effects, which may ensue whilst taking ATENOLOL.
The following is a list
compiled from an actual prescription of ATENOLOL,
highlighting possible adverse effects...
eyes or Conjunctivitis
thinning of hair (very rare)
pulse or mildly slow heart rate (heart block)
As demonstrated above, the
array of side-effects are indeed diverse. Despite the string
of possible effects stated, it has been known that the wide
majority of side-effects are rarely observed, as mentioned
earlier. One is unable to "rank" each side-effect
in terms of their implication(s) on the patient as that
is traced to their relative degrees of effect. In other
words, their relative "danger" is fundamentally
unique to the individual albeit some obviously posing a
greater risk than others. In relation to the table above,
those in red are amongst the many but very rarely observed
side-effects others including sleep disturbances, depressions,
paresthesiae, impotence, exanthema, psoriasis exacerbations
and arthropathies. Primarily, the success of any drug is
based on its ability to solve the prescribed task with the
minimal implications to one's health. Essentially, this
explains ATENOLOL's commercial success.
SO HOW DO THESE
SIDE-EFFECTS ARISE ?
As discussed in the Biochemistry
section, the nature of ATENOLOL as a potent
beta-blocker antagonises the effects of adrenaline. This
effectively lowers heart rate and blood pressure meaning
oxygen may not be in supply at an adequate rate to organs
such as the brain, essentially leading to dizziness, fatigue,
and coldness of the fingers and toes. The lack of oxygen
being supplied to muscles can therefore cause weakness as
well as muscle and rheumatic pain due to the build-up of
lactic acid from anaerobic respiration. The standard advice
is therefore to avoid driving or operating machinery if
on strong doses. In susceptible patients, particularly those
with bronchial asthma, ATENOLOL may cause
difficulty in breathing and aggravation of asthma, generically
known as bronchospasms.
Conjunctivites is one side-effect
which follows a different, adverse secondary pathway. The
conjunctiva is abundant in unique mast cells, which
play a pivotal role in explaining the onset of the condition
whilst taking ATENOLOL. Mast cells release
histamine and other preformed mediators upon stimulation.
Histamine causes itching, hyperaemia, and increases vascular
permeability. As discussed in the definition of mast
cells, during extreme allergic or immune reactions
(anaphylactic shock) they degranulate and produce histamines.
Recent studies have shown that beta blockers, such as ATENOLOL
can induce the degranulation of these mast cells, giving
rise to the irritation to the conjunctiva (please refer
to The Future for further
information regarding these studies). This suggests that
some blockers may possess pseudoallergic attributes that
may account for some of the ocular side-effects of these
Prior in taking ATENOLOL,
patients are required to indicate whether they suffer from
any of the following conditions :
heart problems such as low blood pressure or sick sinus
any type of circulatory disease
In any of the above cases, the patient may not be administered,
or you may require a dosage adjustment or special monitoring
whilst in treatment.
ATENOLOL has been
Pregnancy Category D
by the FDA
(Food and Drug Administration : USA). By virtue, ATENOLOL
is known to have harmful effects on a developing baby. The
use of beta-blockers during pregnancy has been associated
with hypoglycaemia, dyspnoea, bradycardia, and hypotension
in the newborn infant. In addition, ATENOLOL
may pass into breast milk. Implications such
as slow heart rates, low birth weight, bradycardia, hypotension,
and dyspnoea have been reported in nursing babies.
However, complications can
ensue if these side-effects have been traced to ATENOLOL.
It is not merely a case of suddenly stopping the course
of prescription. Alternative drugs must be considered, with
the patient slowly being transferred to them. It has been
known that some people have suffered from chest pain or
a myocardial infarction (heart attack)
if administration of ATENOLOL was stopped
HOW ABOUT INTERACTION
WITH OTHER DRUGS ?
By the inherent nature of
any drug, ATENOLOL may interact with various
other drugs. The main groups of concern are heart, diabeties,
respiratory and gastro-digestive medication due to counter-effects
which may be encountered. For example, whilst ATENOLOL
inhibits the adrenaline pathway thereby reducing blood pressure
levels, an NSAID drug such as Ibuprofen has been
suggested to increase blood pressure. This counter-effect
is fundamentally hazardous to the patient. Each trade name
is given in brackets :
medication such as nifedipine (Procardia, Adalat),
reserpine (Serpasil), verapamil (Calan, Verelan, Isoptin),
diltiazem (Cardizem, Dilacor XR), clonidine (Catapres),
digoxin (Lanoxin), doxazosin (Cardura), guanadrel (Hylorel),
prazosin (Minipress), or terazosin (Hytrin).
diabetes medication such as insulin, glyburide
(Micronase, Glynase, Diabeta), glipizide (Glucotrol), chlorpropamide
(Diabinese), or metformin (Glucophage).
drug (NSAID) such as ibuprofen (Motrin, Advil,
others), naproxen (Aleve, Anaprox, Naprosyn, others), ketoprofen
(Orudis, Orudis KT, Oruvail).
respiratory medication such as albuterol (Ventolin,
Proventil, Volmax, others), bitolterol (Tornalate), metaproterenol
(Alupent, Metaprel), pirbuterol (Maxair), terbutaline (Brethaire,
Brethine, Bricanyl), or theophylline (Theo-Dur, Theochron,
stomach medication cimetidine
(Tagamet, Tagamet HB).
In addition to the above
list, "over the counter" drugs such as aspirin
for example are known to thin the blood, thereby increasing
the rate of blood flow through veins and arteries, essentially
inducing hypertension. Some "over the counter"
indigestion tablets containing calcium or aluminium hydroxide
may reduce the absorption of atenolol if they are taken
at the same time.