Cycloheximde/what to do now?

Bryan dbd2 at
Fri Mar 24 19:30:38 EST 2000

I suspect this is used (cycloheximide) to inhibit eukarya?  Here's some stuff from
California Dept. of health Services.  It does say that use as a fungicide is being
discontinued, but I would guess this should be clinical use.  I would be surprised
if you could not longer use it in research...But I don't relly know.  You could
try something more specific if it is fungi in particular you are trying to
inhibit, maybe amphotericin B.  I found cycloheximide available at VWR scientific
(USA):         But some countries may have changes
regulations on it's use.  Let us know what you find out.



In a recent study, cycloheximide caused birth defects when pregnant animals were
exposed to it at low levels. Cycloheximide also damages the reproductive
systems of male animals. It is not known whether cycloheximide can affect human
reproduction. However, based on the animal studies, HESIS
recommends that cycloheximide be considered potentially harmful to the human
reproductive system.

                              HOW TO KNOW WHETHER YOU ARE BEING EXPOSED

Cycloheximide is an odorless, white, crystalline powder used in hospital and
research laboratories as an antibiotic, a protein synthesis inhibitor, or a plant
growth regulator. Cycloheximide also has broader agricultural use as a fungicide,
but this use is being discontinued due to the recent findings of birth defects
at low doses in animals.

Other names for cycloheximide include Acti-aid,R Acti-dione,R Actispray,R
Actidone, Hizaricin, Kaken, Naramycin, Naramycin A, and Neocycloheximide.

Under the Hazard Communication Standard (General Industry Safety Order [GISO]
5194, Title 8, California Administrative Code) your employer must tell
you if you are working with cycloheximide or other hazardous substances, and must
make Material Safety Data Sheets (MSDSs) for those substances
available to you on your request. Certain laboratories are exempt from these
requirements, based on criteria set forth in paragraph (b)(3) of GISO 5194.

If you think you may be exposed to cycloheximide, you should ask to see the MSDS
for the product involved. An MSDS lists the chemical contents of a
product, describes its health and safety hazards, and gives methods for using and
storing it safely.

Current MSDSs for cycloheximide may not address the reproductive hazards discussed
in this Hazard Alert.

This Hazard Alert is an aid for worker training programs. It does not take the
place of a Material Safety Data Sheet.


Cycloheximide enters your body when you breathe it as dust in the air.
Cycloheximide liquid or powder can also be absorbed through your skin, especially
if there is lengthy skin contact. You can swallow cycloheximide if the dust gets
in your mouth, if it contaminates your food or beverages, or if you smoke or
eat when there is dust on your hands.

Skin: Cycloheximide powders or solutions can irritate the skin, causing symptoms
such as redness, burning, and itching. The symptoms may not occur for
up to 24 hours after exposure.

Reproduction: Cycloheximide causes adverse reproductive effects in male and female
animals at levels below those which cause other toxic effects.
Studies in animals show that cycloheximide causes birth defects when females are
exposed to low doses during pregnancy. In male animals, it is toxic to
sperm and damages the testes. At present, it is not known whether cycloheximide
can cause similar reproductive effects in humans, but, based on the animal
studies, you should handle it as a potential human reproductive toxin and minimize
your exposure as outlined below.

Cancer: Cycloheximide causes changes in genetic material in laboratory tests. This
suggests that it may cause cancer. Cycloheximide has not been
adequately tested to determine whether it causes cancer in animals or humans.

Other: In some animal studies, cycloheximide was toxic to the bone marrow, where
blood cells are formed. The most common effect was anemia (a
shortage of red blood cells). Whether the same effects occur in workers exposed to
cycloheximide is uncertain.

                                     SOURCES AND CONTROL OF EXPOSURE

The highest potential for exposure in the laboratory is during the weighing of
cycloheximide and during preparation of solutions of cycloheximide. The
guidelines below should be followed in addition to the usual careful practices for
handling toxic chemicals in laboratories.

Authorized Personnel: One person should be authorized and trained to handle
cycloheximide in order to limit the number of exposed workers. The
authorized person should store cycloheximide powder in a locked cabinet.

Weighing And Preparation Of Solutions: Cycloheximide powder should always be
handled in a laboratory hood with an appropriate ventilation rate
(see GISO 5154.1). This hood should be in an area not subject to drafts created by
doors, windows, and laboratory cross- traffic. The transfer of
cycloheximide powder should be performed over a disposable material covering the
hood working surface, or over a tray that can be decontaminated
should spillage occur. Disposable materials contaminated with cycloheximide should
be treated as hazardous waste. To minimize contact with
cycloheximide, portions should be weighed out in advance and stored for future
use, when possible.

Cleaning: Cycloheximide is broken down by alkaline solutions (pH greater than 7).
To decontaminate work areas where cycloheximide has been used,
surfaces should be wiped with alkaline solutions. Reusable containers and
glassware which have contained cycloheximide should be rinsed with alkaline
solutions before washing. Almost all soaps are alkaline, so that washing with soap
will break down cycloheximide.

Personal Protective Equipment: Persons working with cycloheximide powder and
solutions should wear tight-fitting, disposable, impermeable gloves in
order to prevent skin contamination and subsequent skin absorption or
hand-to-mouth exposure. Due to lack of test data, no firm recommendation for a
glove material can be made at this time. Common latex surgical gloves may offer
some protection. After use, gloves should be treated as a hazardous waste,
or should be decontaminated by soaking in an alkaline solution before being
disposed of. Even when gloves are used, hands and other areas of the skin
which may be exposed to cycloheximide should be washed with soap and water. As a
good work practice, a lab jacket or apron should also be worn.
Where powders and concentrated solutions are handled within a proper laboratory
hood, respiratory protection is not necessary.

Substitution: An effective way to reduce exposure to cycloheximide is to use an
appropriate substitute chemical. However, careful research should be
performed, to ensure that the substitutes are actually less hazardous.

Sheepskin Hollow wrote:

> We have used cycloheximde extensively in a differential/selective agar
> for Campylobacter- Campy-Cephex Agar.
> We now are finding that the price of the stuff has skyrocketed and I have been
> told it is no longer manufactured.
> Anyone out there know more about this problem or have ideas on what
> we might use for a subsititute.
> Any suggestions for a substitute medium?

More information about the Microbio mailing list