Spermicides

How They Work; Pros and Cons

Composition

Nonoxyl-9

Mechanism of Action

Destroys the cell membrane of the sperm resulting in sperm destruction. Many spermicides are also viricidal and bactericidal.

Dosage

Applied with each act of intercourse. Best used in conjunction with other methods of contraception. Available in many different forms including creams, films and jellies.

Advantages

1. Offers some protection from sexually transmitted diseases. 
2. No hormonal additives. 
3. Can be used in breastfeeding women. 
4. Requires no fitting. 
5. Enhances other methods of contraception. 
6. Augments natural family planning methods. 
7. May prevent accidental pregnancy after a condom break, expelled IUCD or missed oral contraceptive pills. 

Disadvantages/Side Effects

1. High failure rate when used as the sole method of contraception. 
2. Can be messy. 
3. Must be reapplied before each act of intercourse. 
4. Can have an unpleasant odor or taste. 
5. Can be irritating to the penis, vagina or vulva. 

Efficacy

The Pearl Index is as high as 18-28 (failure rate for 100 women using this method for one year). Spermicides are more effective in women whose fertility is already naturally reduced i.e. women over 45 years and women who are breastfeeding.

Contraindications/Poor candidates

Women with sensitivities to spermicides.

Follow-up

None required. The user may benefit from a visit within the first few months of use to discuss side effects as well as overall tolerability.