Pharmaceutical Name: Furosemide
Drug Classification: Loop Diuretic
Active Life: oral: 3-4 hours; injectable 3-7 hours
Furosemide is from a class of drugs called loop diuretics which are a potent
form of diuretic that induce the excretion of water, electrolytes, chloride,
sodium and potassium (1). Medically furosemide is used for the treatment of
such condition as hypertension (2, 3), prostatism (4) and severe bronchial
asthma (5) among others. For strength athletes and bodybuilders the drug is
primarily administered prior to bodybuilding competitions to reduce the amount
of subcutaneous water one is retaining during a competition. Alternatively
some athletes may administer furosemide in an attempt to reduce their
bodyweight for weigh in prior to competition.
Due to the nature of loop diuretics in general the use of furosemide is an
extremely risky undertaking. This is because loop diuretics cause the body to
excrete not only water but also electrolytes, potassium and other minerals.
This can lead to serious conditions ranging from ones as mild as muscle
cramps, although this could be a symptom of a much more severe problem, to
ones including circulatory and cardiovascular disturbances that can lead to
death. There are precautions that users can take to minimize those risks but
they will still exist. For these reasons many users choose to forgo the use of
loop diuretics like furosemide and instead administer other similar drugs that
are potassium and electrolyte sparing but less effective. However there are
still many users that administer furosemide for its extremely potent effects.
Furosemide is produced in both oral and injectable forms with the oral version
coming in tablets and the injectable being able to be administered either
intravenously or intramuscularly, with little difference in the action of the
drug which method is utilized.
So while furosemide may be of benefit to competitive bodybuilders looking to
achieve maximum muscle definition for competition there is little use for the
drug outside of this purpose. In addition there are safer alternatives that
offer similar effects as furosemide. Despite this the drug still remains
relatively popular among athletes.
Use and Dosing of Lasix
Since the reason for using a diuretic such as furosemide is to achieve extreme
muscular definition for a competition, its use is only required for a maximum
of four to five days prior to the day that one wants to achieve minimum fluid
retention. Some athletes will even only require that they administer the drug
the day of an event to achieve the desired results. However of course the time
required for someone to experience the desired effects of furosemide will vary
from individual to individual and personal experimentation will be the only
way to determine how one reacts to the compound.
In terms of dosing, this again will vary from user to user. As will be
outlined in the Risks/Side Effects section of this profile below, the negative
side effects associated with furosemide are extremely serious and thus users
should always begin using relatively small doses of the drug before attempting
larger ones. Doses ranging anywhere from five to forty milligrams are quite
normal depending on the body weight of the user. This holds true for both
males and females, however because of the difference in average bodyweights
females will likely stay closer to the lower end of the range for their
dosing. Some users may experiment with higher doses but no individual should
go beyond eighty milligrams per dose. Any higher and drastic side effects are
likely to occur with any precautionary measures taken by the user to be
unlikely to prevent such negative side effects from occurring. When
administering the oral version of the drug users should begin to experience
its effects approximately one hour after ingesting it. The injectable version,
which can be administered either intramuscularly or intravenously with little
difference in the time it takes for the drug to become and remain active in
the user, should begin producing a diuretic effect almost immediately.
Due to the active life of the drug doses can be administered several times a
day if needed. Of course the dosing with the injectable version of furosemide
will be much easier to manipulate then the oral version. The oral version
primarily is produced in either twenty or forty milligram tablets. Of course
these tablets can be split so that more individualized dosing can be achieved
however more exact dosing can be managed with the injectable version of the
Many users will find that the injectable version of the furosemide produces a
much more intense and dramatic effect then the oral version. This, combined
with the rapid effect that the injectable has, necessitates that users do not
simply use their dosing interchangeably with both versions of the drug. Using
the dose that was effective for the oral version will not produce as dramatic
of results as when used with the injectable. The opposite is true as well with
the injectable producing a much stronger effect if used at what was an
effective dose for the user administering the drug orally with of course the
potential for negative side effects increasing with this. However users have
relatively safely used the same range for dosing of both versions of the drug,
approximately five to as high as eighty milligrams per dose depending on how
well the user tolerates the drug.
Side Effectsand Risks while using Lasix>
The use of furosemide is considered one of the riskiest practices for
competitive bodybuilders to undertake due to the excretion of potassium and
electrolytes that the drug induces. This can lead to both dehydration as well
as an imbalance in levels of electrolytes and/or various minerals. Symptoms of
these conditions can include such things as fainting, diarrhea, dizziness,
moderate to severe cramping and vomiting among others (6). More seriously they
can also lead to cardiovascular and/or circulatory abnormalities which
ultimately could result in the death of the user. In some cases of severe
misuse death can occur quite rapidly.
To minimize the chances of these conditions developing users should of course
experiment with low doses of the drug prior to attempting relatively large
doses. Initial doses in the amounts of five to ten milligrams would be
appropriate for the majority of first time users. Once one has experimented
with the drug and found their tolerance level they can then increase their
dosage as needed.
A second precaution users can take when administering furosemide is to take
potassium supplements to help combat the large amount of potassium that is
excreted while using the drug. Due to the severity of the potassium depletion
that furosemide causes however prescription strength potassium supplements are
likely required. It takes massive dosages of potassium to off set the symptoms
associated with this type of depletion. Without the ability to access such
supplements the user is taking yet another risk.
In cases where individuals do begin to experience severe side effects due to
their use of furosemide users should not attempt to self-medicate by ingesting
large volumes of water, potassium and/or other minerals. By doing so the user
is likely to cause a different type or even more severe electrolyte/potassium
imbalance in their body then already exists. Once severe symptoms begin to
materialize in a user he or she should seek medical assistance to rectify the
condition and not ignore the symptoms or attempt to treat themselves.
Conditions serious enough to cause death can result and it should be treated
Furosemide and other loop diuretics pose no further risks that are specific
only to females (2). There is no evidence that the drug effects fertility or
the hormonal balance in females. Of course like other drugs furosemide should
not be administered to pregnant or nursing women without consultation with a
medical doctor. However beyond the dosing ranges used by females likely being
lower then those of men because of their relatively lower body weights when
compared to the average male females should not face any additional potential
side effects to those already listed and shared by males.
1. Rejnmark L, Vestergaard P, Mosekilde L. Fracture risk in
patients treated with loop diuretics. J Intern Med. 2006 Jan;259(1):117-24.
2. Xu B, Makris A, Thornton C, Ogle R, Horvath JS, Hennessy A.
Antihypertensive drugs clonidine, diazoxide, hydralazine and furosemide
regulate the production of cytokines by placentas and peripheral blood
mononuclear cells in normal pregnancy. J Hypertens. 2006 May;24(5):915-22.
3. del Castillo D, Campistol JM, Guirado L, Capdevilla L, Martinez JG, Pereira
P, Bravo J, Perez R. Efficacy and safety of losartan in the treatment of
hypertension in renal transplant recipients. Kidney Int Suppl. 1998
4. Delaney JA, Levesque LE, Etminan M, Suissa S. Furosemide use and
hospitalization for benign prostatic hyperplasia. Can J Clin Pharmacol. 2006
5. Telia A, Tutashvili M, Donguzashvili S, Pirtskhalava N. Effect of magnesium
and furosemide on bronchial asthma. Georgian Med News. 2005 Nov;(128):55-9.
6. Mentes J. Oral hydration in older adults: greater awareness is needed in
preventing, recognizing, and treating dehydration. Am J Nurs. 2006
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