Short Answer:
The prescription medications are Valtrex, Acyclovir, Famvir, and Denavir.

Long Answer:
There are several medications available, both over the counter and prescription. Only you and your doctor can decide which treatment is best for you.

Valtrex is used to treat certain herpes infections, including herpes zoster (the painful rash known as shingles), genital herpes, and herpes cold sores on the face and lips. Valtrex should not be used by anyone with a weak immune system, such as those with HIV infection or those who have undergone a bone marrow or kidney transplant. Valtrex can cause serious side effects, including death, in such people.

Acyclovir cream (Zovirax) is FDA approved for the treatment of recurrent cold sores. In studies, frequent application of the cream reduced the time to healing by about half a day. Oral acyclovir given five times a day for primary gingivostomatitis in children shortens the course from 10 days to four days and reduces the duration of fever, eating and drinking difficulties, and viral shedding. Using low dose oral acyclovir for cold sores shortened the duration by about one day but did no t have an influence on the pain. Using a higher dose and starting during the prodrome phase did have an influence on the pain and the duration of symptoms.

Famvir is an antiviral drug. It slows the growth and spread of the herpes virus so that the body can fight off the infection. Famvir will not cure herpes, but it can lessen the symptoms of the infections. Famvir is used to treat infections caused by herpes viruses. Illnesses caused by herpes viruses include genital herpes, cold sores, shingles, and chicken pox.

Denavir is a cream containing antiviral medication. Denavir is used topically for the treatment of recurrent cold sores on the lips and face, associated with the herpes simplex virus. It works by preventing the herpes simplex virus from growing and should begin applied at the first hint of a developing cold sore. Denavir may also be used for purposes other than those listed.

Short Answer:
The price, their manufacture, what they are used for and how they work.

Long Answer:
Valtrex, made by GlaxoSmithKline usually comes in a 500 mg pill and is for the treatment of Genital Herpes, shingles, cold sores.

Acyclovir, made by Various Manufacturers, usually comes in a 200mg or 400mg pill and is for the treatment of Genital herpes, shingles, cold sores.

Famvir, made by Novartis, usually comes in a 500 mg pill and is for the treatment of Genital Herpes, shingles, cold sores.

And

Denavir, made by Novartis, comes in a topical cream and is for the treatment of cold sores.

Short Answer:
Abreva, Anbesol, Zinc, Zilactin and more.
Long Answer:
An over-the-counter medicine called Abreva (generic name docosanol) may help cold sores heal faster and reduce the bothersome symptoms associated with them.
Zap it with zinc. Several studies show that a water-based zinc solution, applied the minute you feel that tingling, helps speed healing time.
Other over-the-counter products can help relieve the discomfort of cold sores, but they don’t help them go away faster. To relieve dryness and help keep the sores soft, use products containing the ingredients allantoin, petrolatum, or cocoa butter. Examples of these products include Blistex lip ointment and Carmex ointment.
For pain relief, try products that contain local anesthetics. Anbesol cold sore ointment contains benzocaine, and Zilactin ointment contains benzyl alcohol to relieve pain. You can also use pain relievers such as acetaminophen (brand name Tylenol) or ibuprofen (Motrin and Advil).
If a cold sore becomes infected, apply an antibiotic ointment such as Polysporin three to four times a day. If sun exposure tends to reactivate your cold sores, use a lip sunscreen.
Talk to your doctor about prescription therapy if over-the-counter medicines don’t relieve your discomfort or if the sores remain for more than 14 days.

Short Answer:
Ice, tea bags, lemon balm and many more.
Long Answer:
Pressing or rubbing ice on a sore is possibly the best-known home remedy for cold sores. If the ice is applied early in the development of the cold sore, it can slow down the growth of the area around the cold sore. It is effective to hold the ice on the sore for a few minutes every ten minutes for a few hours. The ice will also help to make the sore smaller and keep the virus from moving or spreading.
Use a warm tea bag on a cold sore. Press it to your mouth for 20-30 mins.
Use Echinacea and goldenseal extract mixture. Echinacea is an immune system booster that can also prevent a cold sore outbreak. Take one dropper-full a day for no more than 3 days. Also put a few drops on a cotton ball and place on the affected area for a few minutes several times a day.
Lemon balm contains a high concentration of polyphenols and appears to minimize herpes outbreaks. It can be applied topically in cream form. Or brew as a tea lemon balm can be taken internally as it has antiviral qualities.
Olive leaf extract is good as a natural antibiotic for viral infections.
L-Lysine fights that virus that causes cold sores. Take 500 mg twice a day.
Vitamin B complex is very important for healing and immune system functions. Take 100 mg of each major B vitamin twice a day.
Place a small amount of salt on the cold sore and hold it in place with your finger for a minute or two. This may be painful but it is one of the quickest ways to heal cold sores.
Cut garlic in half and place one part on the cold sore. A compound in garlic cold Kyolic has antiviral properties which speeds healing. Take 2 garlic capsules a day.

Short Answer:
If the sore has not healed within two weeks, or if you are having complications.
Long Answer:
At times when cold sores still exist after two weeks, an infected person is prompted to seek medical advice. A person attacked by cold sores for the first time usually shows severe symptoms. The first attack is often associated with bleeding gums, fever, a lot of agonizing sores, and swollen glands. People often seek medical assistance in order to help ease or lessen the painful suffering of the infected individual. Worse attacks or symptoms often make a person have difficulty in eating and drinking. In this case, a person is more likely to experience dehydration which needs immediate medical attention.
Individuals with a weak immune system are the ones who are most likely to have the worst outbreaks of cold sores. A sever outbreak can trigger various complications and an infected person should acquire medical help. In order to lessen the frequency of the attacks, medical assistance is very important.